This Yale PM444 Mortice Bolt, also known as a Rack Bolt, Spline Key Bolt, or Star Key Bolt, is designed for use in domestic, industrial, and commercial settings. Available as a set with either one bolt and one key or two bolts and one key, it features a 41mm by 19mm faceplate, 15mm diameter body, and a 60mm body length with a 10mm bolt throw and 32mm backset. The PM444 package includes one bolt, one key, escutcheon, strike plate, and fixing screws, while the PM444M includes two bolts with the corresponding accessories. Additional keys can be purchased separately.