German Tank Crew

 Early war photo of German Panzerkampfwagen IV Ausf.C or D (Sd.Kfz. 161) driver wearing the beret-type "Schutzmütze" (protective cap). This headgear consisted of the soft padded crash helmet, which served to protect the heads of the panzer crew from injuries sustained when the vehicle was motoring over rough terrain, and the black cover. The helmet was circular in shape and manufactured with 1.5cm thick felt or red rubber sponge. The exterior was covered in black cloth and the interior was covered in black oilcloth and a leather sweatband. Additionally there was a 3.5cm cloth covered rubber sponge around the circumference of the helmet with a groove to hold the elastic band of the cover in place. There were six ventilation holes in a circular pattern and one center hole. The cover was an oversized black wool beret with an elastic band to hold it in place on the helmet. The cover contained the insignia on the front. Early insignia included a woven wreath with a stamped metal cockade and no national emblem. By order HV 35, No. 646, dated 30 October 1935, a standard had been established for the wearing of insignia on the black panzer beret. It consisted of a woven wreath and cockade using white cotton, later changed to silver-gray, on a black backing. The national emblem was also woven with white cotton, later changed to silver-gray, or aluminum wire for officers, on a black backing. By order HM 41, No. 64, dated 15 January 1941, the black panzer beret was abolished and replaced, however, it was maintained for crews of the Panzer type 38(t), of Czech manufacture, for drivers and co-drivers of armored personnel carriers, and according to order HM 41, No. 277 dated 7 March 1941, for drivers and co-drivers of armored tractors of the type Sd.Kfz.251. Although out of production in 1941, it continued to be worn after this date.

Source:
http://www.panzerworld.com/uniforms-heer-headgear
http://www.ww2incolor.com/german-armor/Early+war+tank+crew.html