1.用于测量小孔内径尺寸 For small holes diameter measurement. 2.带可换测头，测量范围大 Changeable anvils for wide measuring ranges. 3.配φ42mm表圈小型百分表 Equipped with a φ42mm small dial indicator. 4.不锈钢淬火测头 Stainless steel hardened contact points.
