Fixing Punctures / Puncture Repair / Exploding Tubes

These used to be fairly ubiquitous on old low-quality German bikes, but I don't think they're really fitted any more. I could be wrong, though, as I try to avoid dealing with that sort of bike. Also known as "Blitzventil", or 'lightning-quick valve' in German.

I bought a folder from Germany fitted with those old school valves (Chinese made).
All my bikes when I was a child had inner tubes with those - you'd have to change the rubber inside the valve on a regular basis. We used to buy a paper bags full of the rubber inserts from tyre repair shops.
Also baby strollers often use Dunlop valves - especially if of oriental origin.