TL;DR: Great stuff I put on our camper roof to waterproof and seal. Seems to work at a great price.I came on Amazon looking for FlexSeal or the Rust Oleum LeakSeal and stumbled upon this stuff with incredibly high reviews.Pricing and Packaging: I got one gallon of white and the price is pretty good when put up head-to-head with the competition. Product showed up padded inside a box inside another Amazon box.Application: I used it on a 1994 19' Starcraft camper trailer that had never been completely sealed. We bought it last year and the previous owner had a small leak spring in the back years prior that he had sealed up. The roof had been heavily caulked around all the vents and seams, but the rest of the roof had never been touched. I applied two coats of the RubberSeal--the first with a paintbrush so I could get it on thick and the second 24 hours later with a 6" mini roller from Walmart. I applied mine inside the garage, but I would wait for a few days of sun before I put it on. I also didn't bother cleaning the roof, although mine was surprisingly clean already.Results: One coat of RubberSeal didn't do a great job of covering the roof. The second coat covered it well enough that it should be fine. This only used half of my gallon jug, so I will probably roll a third coat on just for giggles. The sealant got down into all the cracks and seams of the roof and along where the metal meets the vents and just sealed right over it all. It seems like it had a good bond--I can't scratch or chip it off with my nails.Cleanup: I just tossed my paintbrush and roller cover, but it says to use mineral spirits or baby oil, which I had neither of on hand. Gasoline and paint thinner were both a no-go. Didn't touch the stuff.If I don't update this review, assume that I am 100% satisfied with the product and recommend it to all RV'ers!