Foredom No. 15D Handpiece with Duplex Spring - "Quick Disconnect"Same as the No. 15, with the addition of a Duplex Spring. The spring provides extra flexibility to the handpiece.Duplex springs are subject to breakage. We recommend that only experienced users of flex shaft tools whose work demands the added flexibility consider purchasing this style handpiece. For most users, the "straight" handpiece is the preferrable solution. 9-5/8" long, 1/4" dia. at tip, wt. 5.2 oz., ship wt. 7.15 oz. Member of the Foredom system of "Quick Disconnect" handpieces.