A very nice example of the 1934 - 1941 model of the Soviet "Ready for Sanitary Defense of the USSR" badge. Enamel is in very good condition and shows minimal wear. One link of the suspension chain appears to have been replaced. Displays very well. Screwback reverse with matching nut. 
 
Wearers of the "Ready for Sanitary Defense of the USSR" badge participated in military sanitation, housing hygiene, food hygiene, personal hygiene, physical education and Red Cross work.