27in tilt window balancer

Hello,

These look like our S795-21 with a 21D spring strength option and our S795-27 with a 27C stamp option. The only difference would be that ours uses a screw tab instead of a hook for installation. You may be able to install our 26-200 screw plug in the jamb if the cut out is square and matches the dimensions of the 26-200. If not, let us know and we can discuss having these custom made for you. Thanks for posting!