375 x 3/8 x MT2 NATIONAL INVERT SPOT FACER PILOT 3 SPLINE DRIVE ARBOR TOOLHOLDER
Morse Taper / MT2. For use holding in spot facers cutters or countersinks with 3 spline. 375, National drive # 375. Marked as "3/8 NATIONAL PAT. #2120623 "C" "X" #375-2M". Illustrations are shown for general reference or style use only.