Clasp of the Dagger (3.5e Equipment)
From D&D Wiki
Clasp of the Dagger: The Clasp of the Dagger is a device to secure a cloak or as a belt buckle, but it may also be worn as a brooch. It consists of a circlet of metal with a decorative dagger in a sheath affixed across the circle. When a command word is spoken the dagger may be pulled from the sheath as a free action. When drawn the miniature becomes an Keen Adamantine dagger of the appropriate size for the wielder. The dagger may be returned to the clasp by pressing the tip into the opening of the sheath, doing so will return the dagger to its miniature size.
Moderate transmutation;CL 7th; Craft Wonderous Item, Shrink Item; Cost 14,500 gp, 620 xp (+1) 17,500 gp, 860 xp (+2) 22,500 gp, 1260 xp (+3), 29,500 gp, 1820 xp (+4), 38,500 gp 2540 xp (+5); Weight: .25 lb.; Market Price: 21,500 gp (+1), 31,500 gp (+2), 45,500 gp (+3), 63,500 (+4), 85,500 (+5)