From the Manufacturer:
The X-ACTO precision knife is the original cutting tool for any application requiring a precise, accurate cut. This cutting and trimming tool has been used for years by graphics artists, designers, hobbyists and others for making careful cuts and trims consistently and with confidence. Now you can purchase the original X-ACTO knife (#'s 1, 2 and 5) along with a full set of X-ACTO precision knife blades, all in one convenient set, a must have for any art kit.
Hobby Set contains: #1 Knife for precision cutting and trimming of lightweight materials, #2 Knife for precision and trimming of medium to heavy weight materials, #5 Knife for precision cutting of heavy weight materials; #7, #10, #11, #16, #17, #2, #18, #19, #22, #24 precision knife blades.
Deluxe 33-piece Set contains: #1 knife with #11 blade, #2 knife with #2 blade, #5 knife with #19 blade, 8 blades, including #7, #11, #13, #16, #17, #22, #26, and #28, Jeweler’s screwdriver, Block plane, Balsa stripper, Spokeshave, 2 Routers, 4 gouges, Pin vise, 3 Drill bits, and Coping saw and blades.