NEXEL PMC2112 NEXELITE REPLACEMENT PLASTIC MAT 12""W X 21""D - CENTER MAT NEXELITE POLYMER COMPOSITION SHELF MATS HAVE A MODULAR DESIGN ALLOWING EASY REMOVAL FOR CLEANING. THEY HAVE A VENTED OPEN GRID SURFACE THAT IS SMOOTH AND CREVICE-FREE. POLYMER MATERIAL WILL NEVER DENT CHIP RUST OR CORRODE. THE WIDTH AND DEPTH OF YOUR SHELF WILL DETERMINE THE NUMBER OF CENTER AND/OR END PANELS YOU NEED TO PURCHASE. FOR EXAMPLE A NEXELITE SHELF MEASURING 42""W X 18""D WOULD REQUIRE (1) 12""W X 18""D CENTER PANEL AND (2) 15""W X 18""D END PANELS.