Extra Large Die Set, 6 Piece Set | CRY-905.20 Ideal for larger oversized watches with snap-on case backs Made of nylon 3 flat on both sides (35, 40 and 45 mm) and 3 double sided concave (40/42.5, 45/47.5, 50/52.5mm) Goes perfectly with CRY-905.00 Easily snaps on and off quickly