Marks USA's Grade 1 Mortise Locks are BHMA Certified, meet ANSI specifications and are backed by the Company's legendary Lifetime Mechanical Warranty. The mortise locks are thru-bolted for proper alignment and ease of installation, have self-adjusting spindles and independent lever support springs. Available with an ever-increasing variety of knobs, levers, roses and plates, as well as custom trim, Marks USA's 5 Series Mortise Locks can easily accommodate even the most challenging customer needs.