While the Pro Locker by TJM isn't anything new per se, it is something that should soon be more widely available for the Jeep JK Wrangler Dana 30 and 44 axles. From all that I've seen of it, I'd have to say that it's definitely worth at hard look and definitely a contender against the ARB. While it too uses air, the operation of it is different and may even be more solid. Check it out...