Orange Seal is our preferred tubeless sealant for its quick sealing, long life span and lack of funky, acrid odors. One 4oz bottle will provide enough sealant for two tires up to 700x45 or one MTB tire. Plus (~3") or Fat (>4") tires will require more - up to 8oz per tire for the biggest rubber.
Carry one of these handy refill bottles in case you need to make trailside tubeless repairs. The twist-lock applicator makes injecting sealant through your valve easy and the included dipstick is handy for checking your sealant level.