Drywall sanding sheets in 11-1/4 x 4-3/16 in. ceramic blend, sized for a standard pole sander head, plus a Warner pole sander to run them on. Grit goes from 80 for knocking down ridges and heavy build-up to 320 for the last pass before primer. Ceramic blend loads up more slowly than plain aluminum oxide in joint compound, which is what you notice on a full ceiling.
