Left and right plastic top sash guides.
60 Series Channel Balance Accessory.
Base length: 7/8 inch
Base width: 11/16 inch
Cap width: 1 inch
Base-to-cap height: 9/16 inch
Priced and sold as a pair.
This product is similar to or the same as the following part numbers in these brands:
Strybuc Industries: 60-619