Masterview sash window. Plastic part attached to the sliding (top) sash side rail. Four guides per sash, they keep the sash centered in the frame. Attached images show the part installed, removed and the dimensions.
Dave Sr. from SWISCO responded:
April 8, 2015
Take a look at our 67-002 and 67-015. Could you use either of these face guides as a replacement? The dimensions are different, but they appear to be the best matches we have. You may need to redrill the hole.