This inventory item is of the type known as "red herring", which is used to describe useless items in adventure games. Usually, such items are harmless, but in this case, it will result in Roger's death if it's in his inventory while entering the Sewers. The item was added to the game to make fun of a habit of adventure gamers to "pick up everything that isn't nailed down", regardless of whether or not they can see any logical use for the item. The only use from this item is a score point earned when it is picked up, and another when it is put back in place.