Truth Operator 9-1/2". This new style replaces the older tradiational size shown in the diagrams.
To determine hand of operator, if your sash lock (window lock), is on the left, you would use a left hand operator. And if your sash lock is on the right, you would order the right hand operator.
We sometimes find the number 45251 cast on the housing, and 40049 and 40050 stamped on the arms
Left hand shown. The Wi11454 handle in matching color is included