Hold Fast Wide-Body Sealant Injector

The Hold Fast Wide-Body Sealant Injector works with Presta valves only. If your tubeless wheels run Schrader valves, this is not the injector for them. Capacity is just over 5oz, a single fill for most mountain bike setups and enough for any road, gravel or cyclocross tire. To inject, slip the hose onto a Presta valve with the core removed.

Take the plunger out and the injector becomes a funnel for pouring sealant in. It also works as a vacuum syringe when you change tires: pop one bead off the rim, draw the old sealant out, fit the new tire, then put the sealant back in through the valve. Hold Fast suggests 1.7oz (50ml) of sealant per 1 inch of tire width.