Dunlop valve cycling tubes

Dunlop

— a kind of nipple, known to many from old Soviet-made bicycles; nevertheless, it continues to be used to this day, although not as widely as other varieties. The base of such a nipple has a diameter of about 8 mm, the end is noticeably thinner, and between them there is a washer, which, when unscrewed, opens the air valve. Note that with Dunlop, you can use not only "native" pumps, but also devices for a Presta type valve (see the relevant paragraph).