The Tubeless Sealant Refill Kit keeps an already-set-up tubeless tire sealed without ever touching the bead. The injector draws Ultimate Tubeless Sealant's carbon-fiber formula straight from the bottle and delivers it through the valve core, so refreshing a tire's sealant becomes routine maintenance instead of a repair. The 500-milliliter bottle carries enough sealant for several refill cycles across one bike or a couple of wheels. What Our Gearhead(R) Experts Are Saying:"I top off sealant every few months now as part of normal upkeep, not just when a tire's already lost pressure. Core out, sealant in, core back in, and I'm back on the bike in under five minutes."