Solar water heater collector Colour:Black Material:EPDM ,Silicone; Hole:11or 12.shape:round ,rectangle. 1.About productSolar water heater collector for swimming poolSpecificationsswimming pool solar heating systems ... ,silicone tubing,silicone sponge sheet/strip/rod/extrusion, silicone sponge tube,Silicone Fiberglass tubing,PVC tubing,heat shrink tubing,Teflon/PTFE ...