Each blade is 21″ long, has a 5-point star center hole, is 3″ wide, is .164″ thick, has 0″ offset, and 1″ rise. Replaces Ariens: 138971, 138498, 704429, 21546095, 532138971, 532138498 Fits Ariens 42″ Cut: 936007, 936037, 936038, 936041, 936042, 936045, 936046, 936047, 936048, 936049, 936051, 936052, 936060, 936061, 936064, 936065, 936070, 936073, 936074, 936076, 936079, 936080, 936083, 936084, 936087, 936091, 936092, 936093, 936094, 936100, 936101 This is an item that is sold with additional items, such as a camera that is sold with a lens and a camera case. In comparison, a “lot” refers to multiple units of the same item that are sold together, such as two packs of batteries