This pad replaces the top/upper portion of your two piece foam drive pad. (upper foam drive pad) that originally came with your Orbital Pro 1201 Buffer/Polisher. The OP Foam Drive Pad is in two pieces for replacement pad ease of use and for using with foam pads that have other purposes.
The upper Foam Drive Pad is always to be used with an 11" Bonnet for general detailing purposes. Do not put waxes or other chemicals directly on this pad.