All information below is provided by Uninsured United Parachute Technologies, LLC - developer of the Skyhook.
In the last 10 years, 24 jumpers in the US alone have died after breaking away and not pulling their reserves. Another 4 died after entangling with their deploying reserve. The Skyhook gets rid of all those arguments for not using an RSL, and actually gives you some very good reasons to use one. And remember, because the Skyhook is a part of your RSL system, it can be released at any time, before or during the jump, by simply pulling the little yellow tab.
What is it and what does it do?
While a normal RSL automatically pulls the reserve ripcord pin following a breakaway, the UPT Skyhook RSL goes two steps further. It automatically releases the non-RSL riser in case the RSL riser was released prematurely (ensuring your reserve will not deploy with half your main still attached). The Skyhook then uses your departing malfunctioned main canopy as a super pilot chute to deploy your reserve canopy, taking about 1/2 second from breakaway to line stretch (reserve canopy out of the bag). This is 3 to 4 times faster than a pilot chute can do alone, and means that the average sport reserve can be open in 75 to 80 feet after breakaway. This puts the argument of which rig has the fastest reserve depolyment to bed forever.
It has been asked if the Skyhook is like the device used on the Sorcerer BASE rig. Although there are similarities, the Sorcerer system is designed for an externally mounted RESERVE hand deployed system and lacks the automatic release features of the Skyhook making it unsuitable for use with internal spring-loaded pilot chute rigs.
The Skyhook sits inside your reserve container, on top of the #2 kicker flap, right under your reserve pilot chute. A small cover flap protects the Skyhook assemblage.
The Skyhook Lanyard is approximately six inches long, and branches off from the normal RSL lanyard. A specially designed metal "cam" to receive the loop is attached to your reserve freebag bridal, about five feet below the pilot chute. If you disconnect the RSL, you also disconnect the Skyhook.