The celestial robe top is a piece of the Tier 11 celestial robe set released with the Dungeoneering skill. It requires 99 Defence and 99 Magic to wear. As with all Tier 11 items, players cannot make this armour and the robe top is only available as a boss drop from the Warped Gulega.
Although the robe itself does not have a dungeoneering requirement, It can only be obtained by fighting the Warped Gulega, thereby making 95 Dungeoneering a requirement for obtaining and wearing it.