The Guthix platebody is a Treasure Trail reward (though it can be traded to free players) that is green-trimmed version of the Rune platebody, boasting exactly the same stats and requirements to wield. Some players prefer buying these kind of items instead of the originals for either aesthetic reasons, or simply to display their wealth.

Do not be fooled, other players cannot "trim" your items for you! Be sure to ignore and report those who claim otherwise.