When Proselyte armour first came out, Jagex made the mistake of making it a free-to-play item. Free players could obtain Proselyte armour from another player through trade, but not wear it.
Unlike most melee armours with the typical 'metallic' model, wearing Proselyte armour has no effect on the arrow-gathering ability of Ava's Attractor, suggesting that it may not be made out of metal.
The in-game Prayer guide includes 'Proselyte plateskirt' instead of 'Proselyte tasset', but for the Defence skill guide it says 'Proselyte tasset'. The RuneScape Grand Exchange guide on the website also says 'Proselyte tasset', not 'Proselyte plateskirt'.
The biblical term Proselyte refers to a convert from Paganism to Judaism in the New Testament.