Husqvarna 539103230 Lawn Tractor Blade Idler Pulley Arm Genuine Original Equipment Manufacturer (OEM) Part This part is compatible with models including; ZTHQL4221A (968999172),968999172,968999170,ZTHKH4820A (968999158),ZTHQL4218A (968999170),968999158,968999169,ZTHKH4818A (968999157),968999157,968999168,ZTHKW4818A (968999168),ZTHKW4821A (968999169) Blade idler pulley arm 539103230 pivots the idler pulley to apply tension to the blade drive belt, allowing the belt to turn Genuine Original Equipment Manufacturer (OEM) part. Compatible Brands: Husqvarna This blade idler pulley arm (part number 539103230) is for lawn tractors Wear work gloves to protect your hands when installing this part