Dr. Ken Lunde of SigForum.com said:First, at the Beretta LE booth there was the first Rx4 Storm shown, in two configurations. One is the usual pistol-grip style. The other has a different type of stock, which makes it California-legal. It also accepts AR-15 magazines....The suggested retail price of the Rx4 is $960. Also, its Picatinny rail is metal (aluminum or steel, not sure which), not polymer like the Kel-Tec offering.