Displays2go Counter Mats, Non-Skid Rubber Bottom, Countertop Sign Holders for 11 x 17 Inches Images, Slide-in Design - Set of 20 (CMTBK1117) Only sold in case packs of 20 units. Units have side opening, so signs easily slide in/out. Accommodates 11" x 17" signs for convenient promotion. Constructed from rubber w/ a non-glare lens for easy reading. Total Dimensions: 19 1/4" Long x 13 1/4" Wide x 1/8" Thick Viewable Window: 16 3/4" L x 10 3/4" W (allow for a 1/8" border all the way around your 11" x 17" sign) Black Border: 1 1/4" around edge of mat