Consists of inner and outer cylinders fixed to base plate and with lid and top plate; material is aluminum alloy 6061-t6; base plate 8.575 in. Dia, 0.625 in. Thick, with 3.0 in. Diameter hole in center; 16 probe holes and assemblies evenly spaced around outside 4.19 in. Up from top of base plate; probes are 1.015 in. Lg copper beryllium rod 0.125 in. Diameter with steps and tapered to point from 0.0368 to 0.0355 in. Diameter step on one end and to point from 0.098 to 0.096 in. Diameter step on other end; o/a dims 9.155 in. H, 7.953 in. Dia