This 8" Apollo 4A Series double check valve assembly comes with grooved Victaulic OS&Y gate valves. The 4A is a stainless steel bodied, single access cover design that features Apollos patented Triforce check assemblies. The check assemblies are held in place by stainless steel snap retainers. No special tools are required to service the device. The 4A Series are made in the USA and carry a 5 year factory warranty.