Germany, Luftwaffe Utility/"Gravity " knife; Fliegerkappmesser.

The utility knife was introduced in 1937 for parachutists and aircraft crew members. The knife was also known as "gravity" knife because of the special design, which enabled the blade to be extended or retracted with only one hand, using the force of gravity.Two types of utility knives were made during the war. The first one was assembled with no possibility to take it apart, making the maintenance of the knives very impractical. As a result, in the summer of 1941 a take-down version of the knife was adopted, which allowed the knife to be easily disassemble for cleaning and repair. The knife featured nickel-plated stainless steel mounts.The grips covered by wood plates, fixed to the metal plates by pins.The end of the knife has a wire loop.All parts are magnetic.A fold-out marlin spike fixed to the narrow side of the handle, on the opposite side of the lever.Its function was to untangle rope knots, and could also be used as a prying tool. Knife in the excellent condition unused, blade is unmarked, measuring 100mm,spike is marked R.B.NR.0/0561/0019. The Reichsbetreibsnummer(R.B.NR.)was a number system that gave each firm a nine digit code that protected their location and identity. These codes replaced the three letter and number codes in Germany used as a protection against Allied attacks. Name and year markings were replaced with a designated code.This was known as the National Business Number or R.B.NR.The first prefix number was 0 through to 9.This determined the Trade and Industry group. The second group of four numbers is a district code;it identifies the location of the company known as a Kreis, the third set of four-digits was assigned to identify each individual company within that particular Kreis. No master list has survived so most makers are unknown. Our example 0/0561 staying for Solingen.