You may think that you can just wrap your t-bar coater in plastic and throw it in the freezer between coats. I know you do it with your paint rollers, but you can't do it here. Floor finishes dry into the nap of your coater and leave dead spots that leave lines in your floor finish. So, in between coats, you need to completely submerge your coater in the solvent that matches the finish you are using - that will keep it fresh and ready for the next use. The easiest way to do that is with this nifty, if homely, PVC tube, with two end caps. Just pop your coater inside, and fill with the appropriate solvent (water for water-based finishes, mineral spirits for oil-based finishes, denatured alcohol for shellac...you get the idea), pop the cap on and you're done; no mess, no fuss.Sure, you could make one yourself, but will you? This coater saver costs considerably less than just buying another coater. If you have multiple floors and multiple coats on the floors, this is the way to go.