The D+15 type impact device of Mitech portable hardness tester,length: 162mm, weight: 80g, diameter 20mm, has build-in D+15 impact body. It is the type between the D and DL impact device. Compared with the standard impact device, it lengthened 12mm at the front, mainly used for the measurement of narrow grooves and concave surface. It can realize the precise measurements for Leeb, Brinell, Rockwell and others.