Cnc extender adapter made especially for 1/4" Shank router bits., #47642, (D) Diameter 5/8, (D) shank 1/4, overall length (L) 2-5/8, max RPM 18, 000, L1 15/16, L2 1-3/16, L3 1/4, D1 1/4, 47642 1/4 inch Shank CNC extension adapter for 1/4 inch Shank router bits