Casement, Marvin Case-Master and Caradco Old Style Window Casement Hinge Arm (Pair). This Casement Window Hinge Arm Assembly (Per Pair) # 24-EP/24-ER as shown. These hinges are used on the older models which slide in a track that is about 10" long. Some of the 10" tracks have a spring steel wire ring on the hinge track post and some use the clip.