Premium Ultra-Clean™ pure aluminum foil is manufactured specifically for the lab with added strength and puncture resistance. Highly versatile material can withstand extreme heat and cold. Ultra-Clean™ aluminum foil purity helps maintain the integrity of samples. Foil is impermeable to light, oxygen, and water. Premium grade foil eliminates the problems caused by thin, cheap consumer foils which have minute pinholes caused by the production process. The carton has a metal tear-off bar for ease in cutting to size. Unique box flaps prevent the roll from leaving the box. AL-Lab-Pop-Ups™ are individual sheets of foil. Timesaving one-at-a-time single sheet pop-up requires no cutting or tearing. Sheets are ideal for covering flasks, beakers, petri dishes, weigh boats, disposable crucibles, and wrapping samples.