The Moby Multi-Tool is a great key chain tool, great for fishermen or cyclists.

Size: 3.25"L x 1.125"W(fits in your wallet)
Material: 420 Stainless steel 12 (+)

Functions: flat screwdriver, phillips screwdriver, (x6) hex wrenches, headphone wrap, line cutter, 2" ruler, bottle opener, and more.