Viking's Freedom® Model VK472 Residential Pendent Sprinkler has a 5.8 (84) K-factor and is cULus listed for up to 20 x 20 ft (6.1 x 6.1 m) coverage areas. With this larger K-factor, the VK472 can deliver the higher water densities required for an NFPA 13 residential system (0.1 gpm/ft2) at lower starting pressures. Also, the ½ inch NPT thread size allows for installation with a less expensive ½ inch CPVC head adapter, rather than a ¾ inch adapter. The Electroless Nickel PTFE (ENT) coating has been investigated for installation in corrosive atmospheres and is UL Listed as corrosion resistant.