The Sargent 70-8237 LNL 26D is a Grade 1 Heavy Duty Classroom Function Mortise Lock with an LN Rose, an L Lever, and an SFIC Less Core that comes in a Satin Chrome Finish.
Sargent 70-8237 LNL 26D has a 2-3/4" backset and is for use on 1-3/4" thick doors.