Andersen - Perma-Shield - Casement Window Straight Arm Operator LH, Wood, Single Arm, 7193-32Andersen Window Perma Shield Casement Window Straight Arm Operator LH, Wood, Single Arm, PSC, 7193 32, C R, 5 3 8" SHORT ARM 1978 82 7193 7191 32, 5 3 8" . SHORT ARM CR Series, Left Hand Straight arm operator for left hand casement units 1974 to 1995. This operator fits unit widths with the visible glass dimension width of 12 5 8. It is used to replace previous vintage operators with series numbers 7198 17, 1818 2, or 7191 stamped on the back of the