Why the TK25 UV Is Hard to Replace Directly
The Fenix TK25 UV is discontinued, but its combination of white light and 365nm UV in one tactical body is still useful for counterfeit detection and other professional tasks. Finding a direct replacement is difficult because few lights pair a rotary white/UV head with dual tactical tail switches and the same battery flexibility.
Before you shop, decide which feature matters most: the UV wavelength, the 1000-lumen white output, the switch layout, or the ability to run on one 18650 or two CR123A batteries. That priority will narrow your options quickly.
TK25 UV Features Worth Preserving in a Replacement
- Fenix TK25 UV Tactical Flashlight - DISCONTINUED: Rotary flashlight head for free switching between white and UV light. If you need both light types in one tool, this switching method is a key feature to look for.
Fenix TK25 UV Tactical Flashlight - DISCONTINUED - Fenix TK25 UV Tactical Flashlight - DISCONTINUED: Fitted with 365nm UV light and 3000mW UV output. The 365nm wavelength is what makes the UV mode useful for counterfeit currency detection and similar tasks.
- Fenix TK25 UV Tactical Flashlight - DISCONTINUED: Max Lumens: 1000; Max Beam Distance: 738 feet (225 meters); Max Runtime: 110 hours. These numbers give you a baseline for comparing white-light performance in a replacement.
- Fenix TK25 UV Tactical Flashlight - DISCONTINUED: Battery: One 18650 rechargeable Li-ion battery or two 3V CR123A lithium batteries. Battery type is often the deciding factor if you already own 18650 cells or CR123A disposables.
Check Battery Type Before You Buy a Replacement
The TK25 UV runs on either one 18650 rechargeable Li-ion battery or two 3V CR123A lithium batteries. If you have a stock of 18650 cells and a charger, a replacement that uses the same cell will save you money and simplify your kit. If you prefer the long shelf life of CR123A batteries, look for a light that accepts them.
The catalog does not confirm which current Fenix models support both battery types, so verify compatibility in the product specifications before ordering. Also note that the TK25 UV has reverse polarity protection to guard against improper battery insertion, but that does not make it safe to ignore the manufacturer’s battery specifications.
Replacement Paths to Consider
- Another Fenix tactical light with white light only: If UV detection is occasional, a dedicated white-light tactical light may cover most of your needs. You lose the UV mode but keep familiar Fenix build quality and switch logic.
- A separate UV flashlight: Pairing a white-light tactical light with a small UV light gives you flexibility and often better UV performance for close inspection work. The tradeoff is carrying two tools.
- A dual-light model from another brand: Some competitors offer white/UV combinations, but check the UV wavelength (365nm is preferred for currency detection) and battery type. The catalog does not confirm specific alternatives, so compare specifications carefully.
- Keep your TK25 UV running longer: If your current light still works, a fresh battery and basic contact cleaning may extend its service life. See the care notes below.
What to Do If Your TK25 UV Acts Up
If your TK25 UV flickers or fails to illuminate, the catalog lists two common causes: the battery needs replacing, or the threads, PCB board contact, or other contacts are dirty. Clean the contact points with a cotton swab soaked in rubbing alcohol. If that does not solve it, replace the battery, making sure it is inserted according to the manufacturer’s specifications.
For storage or transport, unscrew the tail cap half a turn or remove the battery to prevent accidental activation. If the light will not be used for an extended period, remove the battery to avoid damage from electrolyte leakage or battery explosion. To maintain a proper water seal, replace the O-ring with an approved spare when it shows wear.
Accessories That Carry Over
- Fenix TK25 UV Tactical Flashlight - DISCONTINUED: Compatible with AER-03 pressure switch. If you already own an AER-03, it may work with a replacement light only if that model also lists compatibility.
- Fenix TK25 UV Tactical Flashlight - DISCONTINUED: Included: Lanyard, holster, spare O-ring, body clip. These accessories are sized for the TK25 UV, so they may not fit a different model.
A Practical Way to Move On
Start by listing the TK25 UV features you actually use: UV wavelength, white-light output, switch style, battery type, and pressure-switch compatibility. Then compare replacement candidates against that list, checking the specifications for each. If you cannot find a single light that matches all your priorities, a two-light solution (white tactical plus dedicated UV) is often the most reliable path.
The catalog does not confirm a direct successor to the TK25 UV, so treat any replacement as a compromise and verify the details that matter most to you before purchasing.
