Koolance RP-452X2 Dual 5.25" Reservoir for 1-2 D5 Laing Pumps Rev 1.2 (Revision 2.0 includes a 180-degree copper pipe and acrylic bypass piece for optional serial installation.) Easily combine Koolance's highest flow pumps into dual or serial/redundant loops! RP-452X2 is a dual 5.25" bay reservoir designed for one or two Koolance PMP-450 or PMP-450S pumps (not included). Using a convenient bottom plug, the front reservoirs can be separated or combined without disassembling the unit. Both front and top fill ports are available for each reservoir. Machined from a solid piece of acetal for maximum reliability, the RP-452X2 has a thick acrylic window and front aluminum bezel. Two sets of G 1/4 BSPP (parallel) thread inlet and outlets appear on the back, designated "P1" and "P2" for each pump.