Comparison : Item # 501, Hydraulic Coupling Sockets, Series 500, 1/2" Nominal
Item # 510, Hydraulic Coupling Sockets, Series 500, 1/2" Nominal
Item # 530, Hydraulic Coupling Sockets, Series 500, 1/2" Nominal
Item # 550, Hydraulic Coupling Sockets, Series 500, 1/2" Nominal
Item # 500-A, Hydraulic Coupling Sockets, Series 500, 1/2" Nominal