4dia. 0.740-0.760 in., has one flat side, 0.310 in. Thick; has two holes w/dia. 0.128 in. And 0.096 in. Through face of spacer and one w/dia. 0.031 in. Through thickness of spacer; material is plastic rod polyvinyl chloride iaw l-p-1036, type ii, grade gu