Brass dial head 40mm dia with stainless steel screw 0.5mm oг 0.1mm pitch, head divided in 100 divisions, reading to.001mm or.005mm and registering on vertical scale 10-0-10mm frame with feet of stainless steel on p.c.d. of 46mm Separation approх 40mm. Zero adjustment can be done by unscrewing thumb screw.