The DOT Type I curtain is the base model from which the other three build on. It consists of 18oz, 22oz, or 24oz PVC coated fabric, a solid closed cell foam float, skirt length made to fit your job requirements, and a galvanized chain ballast. There is a strip of 2″ webbing that runs along the length of the skirt on both ends that is punched with #4 grommets every 6″. It is common to use nylon rope to tie this together, ACME also offers toggle pins as an option for this.