Patriot window balance shoe 1 1/4 inch drop-in (PlyGem #747)

Thanks for writing in. The difference is in the cam. The 15-195's cam has a solid back, whereas the 15-195B cam you can 'see through', just like the one you have. So the 15-195B is the better choice. There is, however, another issue here. Your old shoe has a grooved stem, that allows it to interface with a groove in your old channel balances. Unfortunately, our T-Lock Shoes and Channel Balances do not feature this interface, so you will need to not only replace your old shoe, but your old balance as well. So you will need a Series 795 Channel Balance, in addition to the 15-195B which is sold separately. Let me know if you have any other questions.