Open channel sleeve with a dark, polished-looking finish, a precision turned part from a range made in diameters from 1 mm to 50 mm. The hollow body has a long cut-away along one side that opens the bore into a channel, and a slot splits the top end into two prongs. The parts are produced from ferrous and non-ferrous metals in lot sizes from 1000 to millions of parts. Turning runs on CNC Swiss type sliding headstock turning centers, CNC single spindle turret machines, CNC turn mill centers, 2 axis CNC turning centers, multi spindle machines and cam operated Swiss type automatic lathes. Centerless and cylindrical grinding and honing are done in-house; heat and surface treatment are outsourced.