Oskonbyuro (Special Design Bureau) by P. Grokhovsky in the mid thirties of the last century has been active in issues air landing /the air-drop.
Designations G-39, G-40 and G-41 belongs to the family of gauze parachutes. Pretty cheap to manufacture, but more than percale / mulmull intended for the same load. (- Diameter of 5, 10 and 15 meters and weighing 30, 80 and 160 kg., Respectively.)
Universal detachable cockpit G-37, in an emergency or on special assignment was supposed to drop by parachute diameter of 40 m. The designation of the parachute G-№? I do not know (( In any case, it is not G-40.
Plans aircraft G-37 - by Ivnamin Sultanov. magazine "Wings of Motherland"