Hager BB1199NRP Standard Weight Ball Bearing Hinge
4-1/2" X 4-1/2" Five Knuckle, Full Mortise, Non-removeable pin, Stainless steel with stainless steel pin.
For use on heavy weight doors and doors requiring high frequency service. Four ball bearings. Non-rising removable pin with tip and plug. Stainless steel model complies with NFPA80 requirements for use on fire rated door assemblies.