This is a tool, called the Gravity Hook, which can be used just as a 2 pronged hook, as a grappling hook with the addition of a cross-hook or, in its primary format, as a grabbing hook.
It is designed to "bite" objects that might slip out of a grapnel, much like The Claw, from a claw game.
A complete assembly is made up of includes 3 linking bars, 3 "hammer" arms, a cross hook, and nut-and-bolt hardware. A bow-shackle at the end gives you a cord-attachment option.
The whole assembly weighs around 360g in its stainless steel configuration, and a mere 60g in the high-performance Derlin plastic.
Notches cut into the linking bars as channels allow you to affix o-rings, which really help when tightening hardware. They are used to help keep the jaws tightened around the cross-hook whilst set up in the grappling hook configuration, and also during modification by keeping the parts lined up, to let you thread the bolts more easily. I've covered a small grappling hook before but this blows that right out of the water.
Bear in mind that the two version I have are prototypes, and by following along with the Kickstarter campaign there have been several improvements thus far. Notches in the jaws where the cross-hook sit should eliminate the slight wobble that the base of the cross-hook gets when in the grappling hook configuration. This was more noticeable in the Derlin prototype, but from the 3D renders I've seen this will be completely eliminated in the production model. The Derlin model also has a double set of o-ring channels, one high, one low.
I tried the low set as a place to store the o-ring I was using, but found that the added tension reduced the bite that the hook had, and combined with the low weight of the Derlin version, I found more success with the o-ring slipped off the hook entirely. The other difference in the two models are a couple of extra sets of holes in the Derlin version, presumably for threading extra bolts through to "lock" the grappling hook in place.
Two designs of cross-hook are seen as well, the solid version in stainless steel retains the weight and all the strength possible, but the cut-away version more closely matches the hammer-arms of the main body, as well as acting as a gear-tie, following n the footsteps of the Fishbone and Piranha.
Compact enough to be stowed on a back pack strap, I also found that the pair of Gravity hooks, along with their cross-hooks, and a length of paracord fit nicely in a Platatac FUP pouch. I carried both around in my cargo-pants for a few days, trying them out on various things to grab and hook, and found that I needed to be careful which side the shackle bolt was sitting but the rest was easy to carry comfortably.
Here's a safety note: the Gravity Hook was specifically designed for retrieving kit and grabbing things. It has not been tested or certified to bare human weight. The guys who designed them have done some car-towing and some anecdotal destructive testing but stress to never use it in a situation where it's failure or dislodging might cause bodily harm or property damage. As with any climbing or salvage work, always use good judgment. You are responsible for your own actions and decisions. In an emergency, you might need to take extraordinary measures, but the risks are also extraordinary. Failure to follow these warnings could result in property damage, severe injury or death. Be prepared for anything, don;t become a casualty.
So, all that in mind, I really like the Gravity Hook. It's going to be a part of my EDC from now on (because I like to roll as heavy as I can get away with). Having this kind of gadget is exactly the kind of thing that I get to be a hero for carrying, at some stage, always. The Derlain version means I even have an airport safe version to take with me on any abrupt mountain-side landing trips I might be on.
Get in quick, back them on Kickstarter and remember: Always prepare to be a better version of yourself. Unless you can be Batman, then be Batman.