Special 9/16 inch diameter small nose key cylinder for Rockwell Mulipoint locks and entry door handle sets. The flat tail piece is available in two lengths, 1-1/8 and 1-3/8 inch for different lock sets
The longer 1-3/8 inch (36mm) is used primarily on the Entrance handles
The Shorter 1-1/8 inch ( 14mm) is used primarily on Deadbolts and Multipoint locks

Cylinder Type: Small Nose, American Version
Tail Piece Length: 1-1/8 inch ( 29mm) 1.14
Cylinder Height: 1 inch (25.4mm)
5 pin locking cylinder w/ 2 keys
Keyway: Schlage 5 Pin SC1
Rekeyable: Yes
Color: Brushed Chrome and Brass

Note: Please measure the length of the tail piece as shown in second image to be sure you get the correct item.