Our Sail Storage Bags will protect your valuable mainsail, jib or spinnaker when stowed away between sails. Our bags are ready to ship and are made right here in the USA from 420 denier coated nylon oxford cloth.. Every seam is double sewn, two rows of stitching, to make seams secure and the fabric is cut with a hot knife to prevent unraveling. This bag measures approximately 16 inches in diameter x 33 inches in length. To measure your sail for fit, fold your sail as you normally would then measure the length and the circumference (girth) of the bundle. The 16" diameter will accommodate a sail roughly 50 inches in girth. If you have questions please contact us. we're always happy and ready to answer your questions.