Have some windows in my 5ver that open from the bottom up.....with the pins locking into a hole in the frame. Got tired of having no adjustment to the opening so I made a small template with holes in that would slide into the inside window frame. Marked the new hole positions with a spring punch....drilled a small hole then used a 21/64" drill bit and made new holes. Now I can open the window anywhere from 1 1/2" all the way up to what the factory had.