The Rexim-Favor features a quick release barrel, and a magazine that is identical to the German MP 40's. The chief interest of the Favor was that it fired from a closed bolt — that is, the round was fed into the chamber by the action of the cocking handle and remained there until pressure on the trigger allowed the firing pin to go forward. Motive power was provided by two coiled springs, one working inside the other with an intermediate hollow hammer. When the trigger was pressed the depression of the sear released the hammer which went forward under the force of the large outer spring, struck the firing pin, and fired the round. Normal blowback then followed until the cycle continued.