3M 32115 Sandpaper, 9 in W x 11 in L, 80 Grit, Aluminum Oxide Abrasive, Brown, Dry

3M™ sandpaper delivers toughness and flexibility for auto body repair projects large and small. This combination of materials makes hand or machine sanding of auto body surfaces faster, easier and more cost-effective. It features tough aluminum oxide abrasive that self-fractures during use for longer life. Abrasive is built on a choice of paper backing from light A-weight paper to heavier D-weight paper for jobs requiring extra support. All of it is resin bonded to resist heat and to reduce dust clogging, helping lengthen the life of each sheet. Choose 3M™ Sandpaper in a range of abrasive-grades for jobs ranging from stripping paint to fine featheredging. This sandpaper works great with Bondo™ body filler.
3M sand paper sheet uses A/O aluminum oxide AO as the abrasive material. 3M incorporates this A/O aluminum oxide AO material into the sand paper sheet forming a grit of 80. The sand paper sheet has a width of 9 in and length of 11 in.
Specification parameters description:

Backing Weight:
Paper and cloth have a lettering scale for backing weight that measures strength of the material onto which the abrasive is mounted. Paper uses the letters A-F, where A is a lighter weight and most flexible and F represents a rigid, heavier backing. Lighter backings are typically paired with finer abrasive grits, suitable for blending and finishing. Coarser grits used for deburring and stock removal rely on a heavier backing. Cloth uses a lettering system of J, X, and Y for backing weight. J weight (jeans) is the lightest and most flexible, X weight (drills) is more durable and recommended for medium duty work, and Y weight is the toughest and least flexible. Fiber backings are made from chemically-impregnated paper to form a very hard, strong backing material. Fiber is used primarily for sanding discs. Polyester film backing provides high strength with a very thin backing and is used for very fine grits. It is more tear resistant than paper backing and is also waterproof.
Grade:
Grade is a measurement of the size of abrasive particles embedded in coated abrasives. It is a more general measurement of the level of precision, and corresponds roughly to grit. A smaller grit number means larger particles and a coarser grade, while high number grits are used for finer work.
Grit:
Grit is a measurement of the size of abrasive particles embedded in coated abrasives. The most common standards for grit size are the United States CAMI (Coated Abrasive Manufacturers Institute) and the European FEPA (Federation of European Producers of Abrasives). A smaller grit number means larger particles and a coarser grade, while high number grits are used for finer work. Grit is generally a unitless measure but is sometimes measured in microns.