Open-weave mesh design is non-loading and coated on both sides for reversible use. Sand screens should be used with standard speed machines up to 350 rpm, and can be used on both sides before replacing. Sand screens are required to be used in conjunction with a backer pad (standard floor pad such as scrubbing or buffing pad, sold separately). 60-80 grit screens are typically used for removing coatings from concrete, and are recommended for use in a wet application due to them being the most aggressive grit. 10 screens per case. this product arrives to most customers in 2-3 business days.