Swapping out the TK12's standard battery tube with this item tube will allow the use of 18650 batteries!

This replacement battery tube, despite it's sometimes being called an extender, does not 'extend' the size of the flashlight - it is a direct, screw-in replacement for the stock battery tube.

• Adapt with Fenix TK12 flashlight, length: 68.8mm, Diameter: 25.4mm
• Compatible with CR123A Batteries & 18650 cells
• Made of aircraft-grade aluminum
• Durable Type III hard-anodized anti-abrasive finish