Multi Seal FlatOut is a one-time tire additive that prevents flats due to punctures up to 1/2" and stops slow leaks around the bead or valve stem or due to the natural porosity of the tire. It's made of synthetic TangleTek fibers including Kevlar and unique DamRight fillers suspended in a special Never-Settle base fluid (non-adhesive, non-toxic, and freeze-resistant). When a puncture occurs, escaping air forces FlatOut into the wound creating an airtight fiber jam. Like a beaver dam, but with the fibers and fillers forming an amazingly durable plug. Plus, it's proven, having been used in military and industrial applications for decades. Unique Trailer Formula is engineered to protect tires on travel trailers, boat trailers, horse trailers, toy haulers, cargo trailers, utility trailers, and more.• One-time additive that prevents flats• Seals leaks for the life of the tire• Quick, simple installation with Easy Dispensing Cap• Seals punctures up to 1/2" in tread Made of synthetic TangleTek fibers including Kevlar Non-adhesive, non-toxic, & freeze-resistant Quick, simple installation with Easy Dispensing Cap | Camping World Multi Seal FlatOut Tire Additive Trailer Formula, 32 Oz