The Stunner missile is yet another development of the Israeli Python heat seeking air-to-air missile. Stunner apparently came out of the work to develop the Spyder anti-aircraft missile. Stunner is a two stage missile that can hit targets 70-250 kilometers away. Israel has released little information about Stunner, other than that it has two stages and uses multiple sensors. Given its origins and configuration Stunner probably weighs less than a ton.
A shorter range version of the Stunner technology is used in Spyder, which is a mobile short range system. Spyder launchers (truck mounted, with four box like launch cells each) can carry either the Python 5 heat seeking missile (3.22 meters/ten feet long, 105 kg/231 pounds, with a range of 15 kilometers) or the Derby radar guided missile (3.6 meters/11.2 feet long, 122 kg/267 pounds, with a range of 65 kilometers). The Derby is actually a larger Python, with more fuel and a different guidance system. Stunner appears to be a slightly longer Spyder/Derby missile with dual seekers in the nose.
The Spyder radar system has a maximum range of 100 kilometers. The missiles can hit targets as high as 9 kilometers (28,000 feet) and as low as 20 meters (65 feet). With boosters (to increase speed at launch) and the right seekers, a modified Spyder could take down incoming long-range rockets.
David’s Sling depends on longer range radars to get target location and speed information to the Spyder/Magic Wand launchers. Once launched, the Stunner is guided to the general location of the incoming rocket until the Stunner's on-board sensors pick it up and then home in and destroy the long range rocket.