The druidic mage top is a reward that can be purchased with tokens from the Fist of Guthixminigame. It degrades with use similar to the Barrows equipment, and may only be traded when completely degraded. It requires level 35 Defence to wear.
Similar to all other armours obtained from the Fist of Guthix activity, it can be degraded for trading purposes by talking to Reggie in the cave and asking him to degrade the item.