How does FlatOut™ Tire Additive by MULTI SEAL® work to rapidly seal punctures?
FlatOut™ is a high-tech system of synthetic TangleTek™ fibers (including DuPont™ Kevlar®) and DamRight™ fillers in a carefully designed Never-Settle™ base fluid. When a puncture occurs, the escaping air carries FlatOut to the hole. The TangleTek fibers cling to the side of the puncture and form a “filter” which entraps the DamRight fillers. Together, they form a plug, which seals the leak instantly with almost no air loss. As the tire flexes under load, the fiber/filler mass compresses to form a dense plug. The process will repeat itself for each additional puncture.
NOTE: There is absolutely no drying, curing or chemical reaction taking place. FlatOut™ forms a mechanical/physical plug. 
Also, the process is the same whether or not the penetrating object stays in the tire. 
How does FlatOut™ Tire Additive by MULTI SEAL® seal leaks and prevent under-inflation caused by slow leaks?
Under-inflation in tires occur:
    ● Naturally because of the porous nature of tire rubber
    ● Because of slow leaks around the rim
    ● Because of slow leaks around the valve stem

FlatOut™ coats the inside of the tire, dramatically reducing porosity. As the additive spreads around the tire and rim, slow leaks from the bead, pin holes in the rim and leaking valve stem problems are fixed in a similar fashion to punctures. 

Because FlatOut™  lasts the life of the tire, the need to frequently “air up” the tire is significantly reduced.