3oaks Multi-Function Ceramic Pocket Knife Sharpener w/ Thumb Guard and Keychain Sleek and Slim Compact Pocket and Key Chain Knife Sharpener Finger Guard To Protect Your Fingers While Sharpening Medium to Fine Preset Sharpening Angles Provide Guaranteed Results MEASUREMENTS: 2" x 1.75" Compact, Lightweight, Durable, and Comes With a Ball Chain