Side panels have extended straps to the bottoms which also serve as a chinstrap. Top inside head pad is missing, Liner is marked 60. What is most interesting is that the inside of the liner is clearly ink marked wioththe maker and Luftwaffe 1937 LBA procurement marking. This style of helmet was fairly common for motorcyclists in the NSKK but also saw service with the Wehrmacht for dispatch riders in the prewar days, By wartime most rider used regual issue steel helmets.
There is some speculation that this particualt type of helmet was used by some aircrews as it provided addition head protection inside aircraft where the chance for hitting one;s head on solid surfaces was significant. Very interesting and rare example of a dispatch or motor cycle operators helmet, .