Main body: pair of main pipes for supply and return water PA66GF30 supply water branch with fowmeter(optional)return water branch with temperature control spool End part:with automatic/manual vent drainswith temperature gauges with drain valves Features: brass and plastic integration, condensation and frost resistant,water supply and return in middle, fouling resistant, PA66GF30 main body.anti aging, with union/oose joint, joinable structure and easy installation