This is a brand new blade set for lawn mowers. Specs are as follows. 3 blades for 61 cut. Length 21″ CH 5/8″ Width 2-1/2 Thick. This replaces part numbers: WM142180B BOBCAT / RANSOMES 1520842 FERRIS 2174 ROTARY 310-078 STENS 315-872 STENS 42180B BOBCAT / RANSOMES 91-209 OREGON 93-008 OREGON 9987 ROTARY Thanks for looking!!