This is the Legge N5762 sashlock lever series, a 5-lever mortice lock designed for residential and light commercial door installations. It features 1000 differs for key variation and meets BS3621:2007 and EN12209 Grade 7 standards. Critical verification: confirm brass forend finish compatibility with door frame material and verify 1000-differ key system matches existing building stock or specify master-keying requirements upfront.