Used on inside for convenient locking without key. 
1" only with polished brass duranodic.

Also available with keyway.   999 keyway with 2 keys.  Polished brass or satin chrome finish.   1", 1-1/8" or 1-1/4". 1" Adams Rite cam.  1-1/8" & 1-1/4" with regular cam.  1" also in duranodic.  Available KA, K2 or KD.