Soft-flex discs with an extra-thin profile for precise finishing and polishing in areas where access is a problem. 3M ESPE 2380 Sof-Lex Extra Thin Contouring and Polishing Kit, Round Eyelet. Easy-to-use system allows you to create high-luster restorations that offer lifelike esthetics. Discs are color coded to allow for easy identification of grit sequence. Pop-on disc technology makes changing discs easier to save you time. Pop-on discs conform to the contours of the teeth for easier finishing and polishing. Extra-thin (xt) discs allow for easier access to interproximal surfaces while offering a slightly stiffer disc.