Personalised Hammer Keyring Build a memory; and fix a good smile. Double sided hammer keyring. Front of keyring is engraved with hammer and back is engraved with your message. Maximum characters handle of hammer - 10; back of keyring - 55. *Internal use is advised; our wooden keepsake keyrings have not been designed for the hard knock life of car keys. Size 4cm x 5.5cm. Material Laminated cherry veneer.