Magnetic drain plug

Aluminum drain plug with magnet. Also works as a fill plug for the gearbox, and you might be surprised how much metal swarf it catches in that position.

Threads are M14 x 1.5 x 10 mm. Takes a 17 mm socket or wrench.

If you have an older Ural that still has the steel drain plugs, stop tempting fate with that and get yourself some aluminum drain plugs. Far less likely to rip the threads out of the oil sump/gearbox/final drive if the plug is aluminum...