Double hung recessed mortise style sash lock.

Used on wood  & Vinyl windows and is designed to be mortised into the sash rail by 11/32 inch. 

Screw holes: 1-5/8 inch (41.3 mm) center mounting holes 
Cam Thickness: 1/4 inch
Material: Die Cast
Handed: Left
Color:  White 

Please note:
This item is similar to 500321; however, this item has a smaller cam. See the 3rd image for details.

Markings: 678102 on housing ( non truth part )