This bit is used to re-groove door and window frames to allow for insulating inserts to block wind and drafts, #43813, diameter (D): 1/8, cutting Height (B): 1/2, shank (D): 1/4, overall length (L): 2-1/4, Type: profile, flutes: 1, 43813 Solid Carbide seal/straight 1/8 dia x 1/2 x 1/4 inch Shank x 1-flute.