Remington was buying Limbsaver recoil pads from SVL, and calling them R3. Looks like they just made their own knock-off version of the Limbsaver, and called it Supercell. Kind of like they did with Ballistic Tip bullets.
There was a recent ad out by Kick-Ezz showing how their pad compared
to about five others including the Limbsaver. The testing was conducted
by a independent testing lab. The Kick-Ezz was the most effective at
reducing recoil. I haven't checked but the report may be available on the