Pro-Form Sheet Material for Vacuum-Forming of TraysSof Tray Classic Sheets are specifically designed to create custom made whitening trays for patients interested in take home whitening treatments. Available in Regular, Medium, and Heavy thicknesses Select Medium (0. 060") for bruxers whitening trays 20 pcs Select Heavy (0. 080") for severe bruxers' whitening trays 20 pcs The Right Thickness for Any Patient Sof Tray Classic Sheets come in three different thicknesses, so you can find the one just right