however, I need a smaller keller roller that fits a smaller sliding window.
I hold it and measure it the same way your pic is for the above part # it measures 1/2" wide across the top and the length seem to be 13/16ths. The barrel roller seems to be the same size as the the 87-138, however the "shafts"that snap the roller in place are shorter.
the overall length of the barrel including the shafts on each end seems to measure 7/16ths.
