Acorn window latch
A quick learner from virginia says:
July 21, 2015
this is a top latch on a tilt in window. It sayd Acorn on it and is spring loaded . the house was built around 1994. it appears there are left and right handed latches. Its about 2&1/4 inches long and 1 inch wide.
Dave from SWISCO responded:
July 23, 2015
Take a look at our 26-165 Acorn top latches. I believe these are what you are looking for.