- 1.TK737 is a high power flashlight with precise focusing design, Convex mirror adopted to achieve a combination of focus beam and flood beam by one hand pulling. 2.Non-slip knurling surface and exquisite workmanship, which makes it comfortable to touch 3.Multiple choice of batteries, it can work with 1*18650 or 3*AAA. 4.Constant current circuit chip for constant brightness. 5.With diffusers specially designed, it can work as a desk lamp, camping lamp, signal stick light. 6.Voluntary purchase of remote cable switch for wide uses. 7. No extension tube anymore