RMI Concealed Tilt-In finger latch for vinyl single or double hung sliding window.
Fits inside the top rail and has a thumb button that snaps into slot.
Used by Heartland Window and others.

Application: Vinyl Single or Double Hung Window
Width: 5/8 inch
thickness: 3/8 inch
Overall Length: 4-9/16 inch
Handed: Yes, Left and Right Hand
Color: White or Tan
Sold Each, As Shown

Related Parts:
503127 - Left Hand Latch
503128 - Right Hand Latch
503129 - Thumb Button