B1. 13 push-in (clamp-on) spigot right
Links to photos of examples:
1976 Vespa Bravo with plastic tank, original
2001 Tomos TX50 original
2003 Tomos MC50 original
This valve is for Vespa Bravos with plastic gas tanks (some 70’s European models and some 1976-77 US models), and for Tomos off-road models. Tomos #237248. It is all metal, well made, and not prone to breaking like the black plastic ones are.