Monarch CBB 18 Lathe Collet Closer Lever Nose with Complete Set of Collets. Honestly have no idea who makes this, there are no markings anywhere. Some of the collets say "Germany" and some have a logo - see close-up picture.
That's it for information. Spindle mount is D1-6 (3 pin version). Collets are 4.262" long with a 2.48" diameter nose. Range is 1/8-1-5/8, actual collet sizes are. Last two pictures are from the lathe that this was removed from.