Type G: O-ring spigot
<img src="https://eng-calculations.com/SVG/EN/EN_1092-1/Type G(and58) O-ring spigot.svg" alt="Type_G(and58)_O-ring_spigot" title="Type_G(and58)_O-ring_spigot">
https://eng-calculations.com/SVG/EN/EN_1092-1/Type G(and58) O-ring spigot.svg