Double hung window part

Question

I don't know what this is called but it allows the bottom sash of a double hung window to be  open a couple of inches but keeps it from being opened any further. Lease see attached pic.

Bob · Accepted Answer

Thanks for posting. This is called a vent latch. Start by looking at our 26-148. This looks similar, but compare to the dimensions below and let me know if you think this matches well with your old one or not.

Alternate image for 26-148

Alternate view of 26-148

Alternate image for 26-148

Alternate view of 26-148