Overview:10” two stage system with two blue filter heads with BSP brass inserts, and two transparent filter housing sumps, wrench and color box. Set includes: FHPRCLx-B-TWIN system, wrench, 2 bacteriostatic centering rings, instruction and color box. System is available with several connection types:FHPRCL12-B-TWIN - 1/2" BSP,FHPRCL34-B-TWIN - 3/4" BSP.