Switches 

The round tail switch is the tactical switch for instant activation.

The tail FlexiSensa Control is the functional switch for mode selection.

On/off 

Tap the tactical switch to silently and momentarily turn on the light, releasing the light will go out.

Fully press the tactical switch till the “click” sound is heard to constantly turn on the light, press again the light will go out.

Mode Switching

In any state, rotate the FlexiSensa Control switch to select the needed mode.

Tactical Mode

With the light switched on, tap the tactical switch to cycle through Turbo→Strobe. The light memorizes the last selected output including Strobe. 

Duty Mode 

With the light switched on, tap the tactical switch to cycle through Turbo→High→Med→Low. The light memorizes the last selected output. 

Lock/Out mode 

In any state, rotate the FlexiSensa Control switch to lock mode to turn off and lock the flashlight.

With the light switched on, rotate the FlexiSensa Control switch to Tactical mode or Duty mode to unlock the light and enter the previously used output.

Intelligent Memory Circuit

In Tactical or Duty mode, the light memorizes the last selected output including Strobe. When turned on again the previously used output will be recalled.

Intelligent Overheat Protection

The light will accumulate a lot of heat when used on Turbo output levels for extended periods. When the light reaches a temperature of 60°C or above, the light will automatically step down a few lumens to reduce the temperature. When the temperature drops below 60°C, it will then allow the user for the reselection of Turbo mode. 

Battery Specifications

* It is prohibited to use 18650, 16340 or CR123A batteries.

* 21700 Li-ion batteries are powerful cells designed for commercial applications and must be treated with caution and handled with care. Only use quality batteries with circuit protection will reduce the potential for combustion or explosion; but cell damage or short circuiting are potential risks the user assumes.

Battery Replacement

Unscrew the light tail and insert the battery with the anode side (+) towards the light head, then screw the light tail back on.

Charging 

1. Loosen the light head counterclockwise to reveal the USB Type-C charging port and plug the USB A socket of the charging cable into an appropriate A/C powered USB plug/outlet, then connect the USB Type-C socket of the charging cable to the light. 
2. The indicator will display red while charging and will turn green when fully charged. 
3. Once charging is completed, be sure to tighten the light head to maintain the dustproof and waterproof ability.

Note:

1. When charging fails or the battery is reversely connected, the battery indicator will flash red to remind the user to check the battery.
2. The normal charging time of the included Fenix ARB-L21-5000 V2.0 is approximately 3.5 hours from depletion to full charging.
3. Recharge a stored light every four months to maintain the optimum performance of the battery.
4. The light is unavailable while charging.

Note: This only works with Fenix ARB-L21 series rechargeable battery.

Battery Level Indication 

Each time the light is turned on, the indicator (unscrew the light head to see) will indicate the battery level and will last for 3 seconds. 

Green light on: saturated 100% - 85%

Green light flashes: sufficient 85% - 50%

Red light on: poor 50% - 25% 

Red light flashes: critical 25% - 1%

Note: This only works with Fenix ARB-L21 series rechargeable battery.

Low-voltage Warning

When the voltage level drops below the preset level, the flashlight is programmed to downshift to a lower brightness level until Low output is reached. When this happens in Low output, the light blinks 3 times every 5 minutes to remind you to timely recharge or replace the battery. 

Note: This only works with Fenix ARB-L21 series rechargeable battery.

Usage and Maintenance

• Disassembling the sealed head can cause damage to the lamp and will void the warranty.
• Fenix recommends using an excellent quality Fenix battery. 
• Take out the battery to prevent accidental activation during storage or transportation. 
• If the lamp will not be used for an extended period, remove the battery, or the lamp could be damaged by electrolyte leakage.
• Unscrew the tail cap or remove the battery to prevent accidental activation during storage or transportation.
• Long-term use can result in O-ring wear. To maintain a proper water seal, replace the ring with an approved spare.
• Periodic cleaning of the battery contacts improves the lamp's performance as dirty contacts may cause the lamp to flicker, shine intermittently or even fail to illuminate for the following reasons:
  A: Low battery.
  Solution: Recharge or replace the battery (Ensure the battery is inserted according to the manufacturer’s specifications).
  B: The contact point or contact of the battery or flashlight is dirty. 
  Solution: Clean the contact points with a cotton swab soaked in rubbing alcohol.

If the above methods don't work, please contact the distributor.

Warning

• Do place this flashlight in the reach of children!
• Do NOT shine the flashlight directly into the eyes of anyone!
• Do NOT shine flammable objects at close range, to avoid burning objects or causing danger due to high temperature!
• Do NOT use the flashlight in inappropriate ways such as biting in the mouth, to avoid personal injury or life threats when the flashlight or internal battery fails!
• This flashlight will accumulate a lot of heat while working, resulting in a high temperature of the flashlight shell. Pay attention to safe use to avoid scalding.
• Turn off and lock the flashlight or remove the battery from the flashlight to prevent accidental activation when the flashlight is placed in a closed and flammable environment such as pockets and backpacks!
• The LED of this flashlight is not replaceable; so the whole flashlight should be replaced when the LED reaches the end of its life.

Q1. What kind of LEDs are used in TK20R UE? Does Fenix offer to replace LED?

A: A Luminus SST40 LED with a lifespan of 50,000 hours. 

Fenix does not provide LED replacement services for the time being, and users are not recommended to replace the LEDs independently, which may affect product performance and cause product damage.

Q2. What is the color temperature of TK20R UE?

A: Around 6500K.

Q3. What is the operating voltage of TK20R UE?

A: The operating voltage is 3.0 V. The operating current is 4.2 A.

Q4. Is TK20R UE rechargeable? How long is the charging time? 

A: Loosen the light head counterclockwise to reveal the USB Type-C charging port and the indicator. The indicator will display red while charging and will turn green when fully charged. Once charging is completed, be sure to tighten the light head to maintain the dustproof and waterproof ability. The normal charging time is approximately 4 hours from fully depleted to fully charged.

Q5. How to prevent accidental activation of the TK20R UE?

A: Lock: In any state, rotate the FlexiSensa Control toggle switch to OFF/Lock mode to turn off the light.

Unlock: With the light switched on, rotate the FlexiSensa Control toggle switch to Tactical mode or Duty mode to enter the previously used output.

Q6. Why does the TK20R UE downshift to a lower mode after being used for a while and the higher mode cannot be selected?

A: There are two reasons:

1. Intelligent Overheat Protection      

The flashlight will accumulate a lot of heat when used at relatively high output levels for extended periods. When the flashlight reaches a temperature of 60°C or above, the lamp will automatically step down a few lumens to reduce the temperature. 

2. Low-voltage Warning

When the voltage level drops below the preset level, the flashlight is programmed to downshift to a lower brightness level until Low output is reached. 

Q7. Why does the TK20R UE happen to flicker?

A: The reasons that may cause the flashlight to flicker, shine intermittently or even fail to illuminate:

A: Poor battery level.

Solution: Recharge or replace the battery (Ensure battery is inserted according to the manufacturer’s specifications).

B: The contact point or contact of the battery or flashlight is dirty. 

Solution: Clean the contact points with a cotton swab soaked in rubbing alcohol.

If the above methods don't work, please contact the distributor.

Q8. What kind of battery can be used in TK20R UE?

A: Fenix ARB-L21-5000 V2.0 is recommended. Other Li-ion batteries are not recommended. As an unmatched battery may cause the flashlight to fail to work normally.

Q9. What are the optional accessories for TK20R UE?

A: ALR-01 Tactical flashlight ring, ALG-16 M-Lok quick-release rail mount, ALG-00 Rail mount, ALG-18 Rail mount, AER-05 Remote pressure switch, etc.

Q10. Is the TK20R UE battery port waterproof?

A.  The light is waterproof so long as the battery port cover is completely tightened.

Q11. What should I do if the TK20R UE needs repair?

A: 1. 15-day replacement: Fenix will replace identical or equal products with documented manufacturing defects within 15 days of purchase.

2. 5-year free repair: Fenix will repair a light free of charge within 5 years (rechargeable battery: 1 year) of purchase if problems develop with normal use.

3. Lifetime maintenance: If repair is required after 5 years from the date of purchase, Fenix will charge for parts. The total repair fee is dictated by the cost of the replaced materials.
4. If you need warranty service, fill out the warranty form at https://www.fenixlighting.com/pages/warranty-repairs to start your repair claim.