The Sargent 1131 RU TB Door Closer Is a Surface Mounted Grade One Closer For Commercial Applications, Features Full rack and pinion, High strength cast aluminum case, and Thru Bolts. The 1131 RU package is provided with a non-hold open arm which includes an additional bracket that allows the installer the choice of standard, parallel, or top jamb applications. Used on Rated and Non-Fire rated doors. The Sargent 1131 RU Is Adjustable from sizes 1 through 6: Door closers to meet handicapped 1131 requirements or for light through medium weight interior doors, ANSI Grade 1 A156.4, Adjustable backcheck valve is standard, For Use Hotel/Motel guest room, Retro-fit on storefront entry doors, Retail buildings, Interior office doors, Assisted living centers, office buildings.