Flexweave Underlay

Flexweave Underlay is an engineer-only permanent "enchant" to cloaks. It will give a 30 second parachute every 60 seconds. As of 4.0.1 this no longer takes a spot as an enchant, this means both an engineering enchant and a regular enchant can be present on one item.

Source
The recipe for this item is learned from Grand Master Engineering trainers.