Alexander of Red Army Airsoft writes about the Tuffnation Airstock for HPA-powered airsoft M4 rifles that comes with a cylinder and regulator... "Sometime ago on the Vkontakte page of Russian producer WSC systems (Proteus), the company TuffNation posted a 3D model of their new product - the stock with an integrated cylinder and regulator - 'Product PB' ('Butt-cylinder').

It was claimed that the product will work with the regulator's own production of cylinders with volumes from 0.2 to 0.5 liters. This will allow depending on the configuration of the system to make WSC from 750 to 2000 shots (average 8-20 mechanical shops) with one cylinder, which is not very, very bad."

Read the full story here. (In Russian)