Pre-Inked Key-chain Stamp - Impression Dimensions: 3/8" Diameter. This inspection stamp comes in it's own self-actuating protective case. Simply press down and the bottom opens to expose the stamp. It comes on a key-chain so it's perfect for people on the go! The laser engraved rubber makes this stamp strong and durable for years of use. Makes approximately 50,000 impressions before re-inking is needed. Use Xstamper Refill Ink only.