10th squad sigil

A sigil that a player wears to teleport to the last battle in the Monkey Madness quest. Players should not wear it before they are ready. If they lose it they can obtain another from Waymottin, at the end of the Ape Atoll Dungeon. You can obtain two by dropping the first one and talking to Waymottin for another. Glough casts a spell which would summon all members of the 10th squad to the battle site where they were to be killed by a level 195 Jungle Demon. By wearing a 10th squad sigil players were identified as part of the squad and thus were able (hopefully) to aid them in defeating the demon. After the quest, you can wear it. It looks like a medal or award.

From RuneScape Wiki, a Wikia wiki.