This will be for a single hung, non-tilting sash. Only identifying marks are 2790 30. The metal portion of the channel is 1/2" wide, 28 1/16" long. The attachment that hooks onto the window frame is a tab with a triangular hooked tip. Looking through the catalog, it appears to be a Series 351, but the bottom shoe on mine measures 1 1/16" between the 351 and 390 series'. Any help is greatly appreciated.
- Justin