2 TPU presta valve (60mm) tube.

For 18-28mm tyres, typically 100grams lighter than butyl Suitable for disc brakes (though I have used mine on rim brakes all year and no issue) alloy valves rather than poor quality plastic which often fail or leak air

Valve length is 60mm so good for up to 50mm deep rims Packs down to next to nothing, 3 take up the same of one traditional butyl tube and still weigh less.

When installing, inflate the tube before inserting but only enough to give it some shape (5 PSI max). Fit the tyre as normal and as with butyl avoid using tyre lever when fitting to at avoid pinch flats. Includes repair patches and isopropyl alcohol swabs for prepping the area in the event of a puncture.

TPU facts

They have excellent low rolling resistance.  Only a fraction off latex tubes.

2 tubes in your back pocket and two in your tyres, that's 1/2 a KG weight saving.  That's the same weight difference between Dura Ace and 105 groupsets.

Despite being so thin they have strong puncture resistance.  From my experience, a puncture isn't a quick blowout, it's slow and controlled as the hole is tiny.

TPU are easily repairable.  Like with a buytyl tube unless it is right next to the valve I fix and re-use mine.