Your search for "3021" revealed the following:

Surgical Blades Full range with Fitments

Surgical Blades No.3 Fitment Baldes Full Range with Reference No. to fit Handles 3, 3L, 5A, 5B, 7, 9, B3 and B3L.   Sterile Non Sterile   Blade No. Fitment No. Stainless Steel Foil Pack Singles Carbon Steel Foil Pack Singles Carbon Steel Foil Pack 5's Carbon Steel Single Peel...