Pump Stands, P550 and P15W GNC Piston Pumps. Set of 2. Reference #28 42-550-28Parts Diagram GNC P550 Pump Stands. Set of 2. Reference #28 42-550-28SKU: 42-550-28 $69.32 Regular Price$58.92Sale PriceExcluding Sales TaxQuantity*Add to CartBuy Now