This pusher or slider was originally made of black plastic. Ours is made of aluminum for added strength. It measures 9.5 mm in diameter (3/8") x 25.5 mm long (1"). It is used to release the false clamp latch pin assembly. (Equivalent to Polar part number 241828.) This fits Polar models 76 up through the Polar 137. (It does not fit the Polar 155 models, these used a longer slider.)

Each slider comes with one of the black plastic hole plugs or caps as shown in the photo. (The plug is equivalent to Polar part number 241827.)