I buy all my McKee's 37 products by the gallon. It's not because of my employee discount, either. A gallon-sized container makes sense, because after all I'm never going to stop detailing my car! Not only is a gallon-sized refill more cost effective, it's better for the environment too because you're reducing waste! I was tired of using sub-par store-bought bottles to fill from my gallon jugs, so my team and I developed professional-grade bottles and sprayers. Now, I simply refill one of these nifty bottles any time I run out of product.