3.5" diameter self-adhesive vinyl dot sticker, 200 PCS dots per roll; Made of vinyl, reusable & removable gel, durable to use; Dry erase dots: You can use dry erase marker, whiteboard pen, pernanent marker to write and erase at the dots, it's easy to wipe and clean.(Not suitbale for ballpoint pen & fountain pen); Easy to USE & REMOVE: Everybody can install it in a few simple steps, peel & stick, when you remove it, no glue will remain on the surface; Wide application: It can be widely used for floor marking, warehouse marking, pipe markers, social distancing warning sign, directional sign, school teaching, group study, home organzing, business, classroom etc.