The snap-tight design of the 12" x 18" clear Cambro 1218CCW135 Camwear flat lid ensures that it will keep the contents of your Cambro food storage box safe and secure during transport! Plus, your food will stay fresh longer. This flat food storage box lid features molded-in top rails for secure stacking, and is made of durable polycarbonate that can withstand temperatures from -40 to 210 F. Snap-tight covers won't come off during transportation. Top molded-in rails for safer, more secure stacking. Made of crystal clear, virtually unbreakable Camwear polycarbonate. Withstands temperatures from -40 to 210 F (-40 to -99 C).