Operating Instructions for the TK20R V2.0 Rechargeable Tactical Flashlight
Switches
- The round tail switch is the tactical switch for instant activation.
- The oval tail switch is the functional switch for output selection and instant strobe.
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 to constantly turn on the light, press again the light will go out.
Output Selection
- With the light switched on, single click the functional switch to cycle through Eco→Low→Med→High→Turbo.
Strobe
- With the light switched on, press and hold the functional switch for 0.5 seconds to enter strobe, click the functional switch once again to turn back to the general mode.
- With the light switched off, press the functional switch to enter strobe, release the light will go out.
Intelligent Memory Circuit
The light memorizes the last selected output excluding strobe. When turned on again the previously used output of general mode will be recalled.
Battery Specifications
| Type | Dimension | Nominal Voltage | Usability | |
| Fenix ARB-L21-5000 V2.0 | 21700 | 3.6V | Recommended | √√ |
| Fenix ARB-L21-5000U | 21700 | 3.6V | Recommended | √√ |
| Fenix ARB-L21-4000P | 21700 | 3.6V | Recommended | √√ |
* 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 the TK20R V2.0
- 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 electrical outlet, then connect the USB Type-C socket of the charging cable to the light.
- 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.
Note:
- When charging fails or the battery is reversely connected, the battery indicator will flash red to remind the user to check the battery.
- The normal charging time of the included Fenix ARB-L21-5000 V2.0 is approximately 3.5 hours from depletion to full charging.
- Recharge a stored light every four months to maintain the optimum performance of the battery.
- The light is unavailable while charging.
Note: This only works with Fenix ARB-L21 series 21700 rechargeable Li-ion 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 21700 rechargeable Li-ion battery.
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.
Low-voltage Warning
When the voltage level drops below the preset level, the flashlight is programmed to downshift to a lower brightness level until Eco output is reached. When this happens in Eco output mode, 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 21700 rechargeable Li-ion battery.
TK20R V2.0 Usage and Maintenance
- Disassembling the sealed head can cause damage to the light and will void the warranty.
- Fenix recommends using only a high-quality protected battery.
- If the light will not be used for an extended period, remove the battery for proper storage.
- 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 light’s performance as dirty contacts may cause the light to flicker, shine intermittently or even fail to illuminate for the following reasons:
A: Poor battery level.
Solution: Recharge or replace the battery.
B: The contact or contact point 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 your authorized distributor.
Warning
- The flashlight is a high-intensity lighting device capable of causing eye damage to the user or others. Avoid shining the light directly into anyone’s eyes.
- This flashlight will accumulate a lot of heat when used for extended periods, resulting in a high temperature of the flashlight Pay attention to safe use to avoid scalding.
- Do not shine an object at close range, to avoid burning the object or causing danger due to high temperature.
- The LED of this flashlight is not replaceable; so the entire light should be replaced when the LED reaches the end of its life.
- If any of the information provided in this manual is changed, the new version of the manual shall prevail; if your included user manual is an old one, it acquiesces that we won’t send a new manual.
