1.用于內(nèi)尺寸、外尺寸及狹縫外尺寸測(cè)量 Can measure OD, ID and narrow geoove outside dimension. 2.讀數(shù)直觀 Easy reading. 3.整體機(jī)芯,雙向防震 Shock proof. 4.帶微動(dòng)滾輪 With thumb roller.