Zipit Bedding Set, Extreme Sports - Twin Works like a sleeping bag you just zip it! Zipit Bedding is a fitted sheet and a comforter zipped into one fast, fun, and easy unit. Available in multiple colors and patterns, and in full, twin, twin extra long, and queen sizes. Perfect for hard-to-make bunk beds, college dorm beds, trundle beds, murphy beds, squishy air mattresses and more. It's back to school season! Twin and twin XL are the most common sizes for college dorm mattresses. Zipit makes laundry simple too. Simply strip it off the bed, wash, and re-fit as one unit.