The MS series Mortise Lock is BHMA A156.13-2012 certified Grade 1, and UL 10C 3-hour rated. The "R" rose is 5/8" in height and 2-5/8" in diameter. The design of lever surrounded by a ring provides better protection to the lever. Both clutched and non-clutched mortise chassis are available. 8 commercial lever and Knob in 8 BHMA finishes to select from.