S/s, one end 0.250 in. Dia, 0.410 in. Lg increasing with 45 degree cylindrical taper to 0.375 in. Dia; then decreasing with 58 degree cylindrical taper to 0.120 dia, other end. 16 micro in. Finish on tapered surface this end. dim. 0.970 in. Large 0.375 in. Dia