A30 Petcock

A30. 14x1.25 male spigot down

A30 14×1.25 spigot down
D400181  $26
←res  on↓ off→
made in Spain by Ideal

Links to photos of examples:

1978 Derbi Laguna original
1980 Derbi C5 Diablo original
1985 Derbi RD50 original

This motorcycle valve has a 7.7 mm spigot, for 1/4″ (6.3mm) fuel hose.