MTD 754-0280 Replacement belt by Rotary.  Also 954-0280
Lawn Mower Belt For MTD # 754-0280, 954-0280, 954-0280AReplaces Part Numbers MTD 754-0280, 954-0280, 954-0280AOEM Numbers : Engine/Variable Speed Belt. Replaces MTD 754-0280. 5/8" section belt (15.88 mm), 53" length (1346.20 mm). Fits 600 series variable speed unit engines. Also fits 38", 40" & 42" older units. Type : Lawn Mower Belt