Corbin Russwin DL2217 Cylindrical Classroom Cylinder Deadlock, L4 Keyway, Keyed Random, [2] Change Keys, Non-Handed. 

Function: Classroom

By key outside and by thumb turn inside. 

DL2200 Series Cylindrical Deadlocks

• Handing: Non-handed.
• Door Thickness: Standard - 1-3/4" (44mm). Optional door thicknesses are available; see Quick Codes.
• Backset: Standard -  2-3/4" (70mm); Optional: 2-3/8" (60mm)
• Front: Standard - brass or stainless steel, 2-1/4" (57mm) x 1-1/8" (29mm). Optional: 1" width; see Quick Codes.
• Deadbolt: 1" throw, solid steel deadbolt with hardened, free spinning, steel pin insert.
• Strike: Standard - 2-3/4" (70mm) x1-1/8" (29mm). Optional strikes and wrought boxes are available.
• Cylinder: Standard - brass, 6-pin, L4 keyway, Keyed Random. Security cylinder optional; see Quick Codes.
• Keys: Two nickel silver standard.
• Keying Features Available: Master keying; construction master keying; security; visual key control; concealed key control
• Warranty: One-year limited.