Vinyl double hung window tilt latch, slide-In plastic Round end housing, 1/4" wide scallop nose & standard actuator, latch is slightly recessed (not flush) with side of housing
May be interchangeable with other ones that look similar, note the width of the latch width is most important.

Application: Single or Double Hung tilt-in window latch
Housing Width: 11/16 inch
Housing Length: 2-11/16 inch
Housing Type: Round ( Square or Round ) 
Latch Nose: 45° Standard Nose ( Standard or Scallop )
Nose Size: 1/4 inch .248 ( 5 Widths) 503138
Stile Snap In: 5/64 inch .075 ( 5 positions available)
Latch Actuator: Standard
Material: Plastic
Color: Creamy White, Almond (Beige), Clay 
Priced and sold in pairs.

Additional Information:
* Housings are square or round, either will work on most windows
* Latch Bolt are Straight or Scallops, the scallops are mostly the larger widths and are interchangeable when widths are the same.
* Stile Snap in on bottom of housing vary, some have number to ID the offset. This is not critical on most windows. This holds the housing in place so it won't slide out when window is opened.
* Actuator is decorative only, does not matter which one you have, They will all work the same.