Accuracy according to DIN 863 / 3. Surfaces contract tempered and lapped ø 4.5 mm. Micrometer screw stroke mm 25 mm tempered and rectified step or 5 stainless steel high resisteza. Screw sensitive. Drum ø 20 mm. Read matt chrome surfaces. Reading 1 / 100 mm. hardened and ground support base 100 mm. Packed in carton.