It sound like the tutorial is saying
the kit is a variety of materials you would use to insulate between three to five windows. just like the adhesive tape and caulking, these are also simple to install and the rolls come in an assortment of sizes.
the kit mentioned above refers to this kind of things
I cannot understand the last part "the rolls come in an assortment of sizes".
I guess the rolls mean some kind of tapes
assortment means "a miscellaneous collection of things"
does that part mean that the kit contains a miscellaneous collection of things that suitable to a variety of dimensions?