The rubber disk, comes free with the wire!
Though you want to cut out the wire, you will find many uses for the flexible strip that you get as an extra bonus this way. Demotech makes hinges with it for doors and boxes, we use it as washers for the rope pump, but the strip is nog wide enough for cutting shoe soles out of it, unless for the smaller sizes.
Note that the cutting goes best with only a light pull at the disk. When you pull hard, it is hard to steer the knife and the edge gets ragged.