M & J Chimney Service
Our best selling product:

The Butterfly Top-Damper from RMR...
    Old-fashioned dampers are located at the bottom of the chimney. They tend to rust and warp over time, and do not seal well. Even with a screen at the top, they allow the entire chimney to be open to water and insects. This can create a smell, especially in the summer.
     The Butterfly Top-Damper seals the chimney at the top. There is a high - temperature silicone seal at the top that completely seals the entire chimney. The unit pays for itself in heating and cooling savings. It is operated by a cable that latches into a bracket that is mounted in the firebox. It is very simple to operate.
Also comes in a cap / damper model...