Tilt Latch, Slide in Plastic, Pairs in White.

45 degree latch bevel. Housing measures 2-3/8 inches Long, 11/16 inches wide, 7/16 thick.
Has a raised finger pull.
Patent Pending on underside.
Not Interchangeable with other ones that look the same, note the shape of the latch bevel and position relative to housing. 

Note:
This fingerlatch assembly slides into a route.
cut out in the top of the window sash.
Sometimes you can just push and it will slide out.
If not, take a small block of wood and gently tap on the end till it slides out.

Priced and sold in pairs.