This arm has all the characteristics of the CloserPlus arm with an additional steel buffer spring that provides greater protection at the end of the door opening cycle. Door closers shall have built-in door stop [and holder] effective at one point selected at installation, from 85° - 110° in five-degree increments. Door stop mechanism shall be reversible and have a buffer spring that engages prior to the dead stop feature, reducing shock loads to the door and frame assembly. For extreme conditions, use of a Unitrol arm is recommended.