The Upper Wash Arm is an OEM component specifically designed for Whirlpool dishwashers. It is responsible for spraying water across the upper rack during the wash cycle to effectively clean dishes. It measures approximately 7.5 inches long by 1.37 inches wide. Causes of a bad upper wash arm can include mineral or lime scale buildup that clogs the spray nozzles, or damage to the arm itself such as cracks or breaks that compromise its spraying ability. Symptoms of a bad upper wash arm include: Inadequate cleaning of upper rack dishes  Dirty dishes after a cycle Clogged or blocked spray nozzles Visible damage or wear to the arm This OEM replacement wash arm from Whirlpool is compatible with KitchenAid, Jenn-Air, Amana, Magic Chef, Admiral, Norge, Roper, and some Kenmore models as well.Part Number 8193504 (AP3120022) replaces 8268298, 8268299, 8538389, 8538390, 903947, AH392681, EA392681, PS392681.