The RUPES Mille Backing Plate is designed to be used exclusively with the RUPES LK 900E BigFoot Mille gear-driven dual action polisher, and is currently available in two different sizes, with each size being compatible with a set range of Mille foam polishing pads and BigFoot wool polishing pads (see the fitting notes in the How To Use section below). Both sizes are made out of nylon and flexible polyurethane, which together are particularly resistant to mechanical stress. Both sizes also feature a durable hook and loop fastening material, which is specifically designed to be able to withstand the extreme forces generated by the powerful gear-driven movement of the RUPES LK 900E BigFoot Mille, and provide solid anchoring and stability while the machine is in use. The amount of vertical grip, however, is normal, thus ensuring that Mille and BigFoot polishing pads remain easy to affix and remove.