M sigil

The K sigil is a quest item used in the Enakhra's Lament quest. It is found on a pedestal in the ancient underground temple in the desert south of the Bandit Camp. The sigil is used to unlock a door in the temple along with the Z sigil, R sigil and K sigil.

The four sigils together spell the consonants in 'Zamorak', the deity who's honour the temple was built in.