This volume contains 120 pages, approx. 165 photos and 43 historical shots of the gun vehicle with all known variants in b/w, many of them unpublished; 98 coloured photos of existing examples of the Sd.Kfz. 138/1 Ausf. M from the only two surviving vehicles in the US Army Ordnance Museum, Aberdeen and Patton Museum, Fort Knox. 18 coloured photos of both versions from Tony Greenland, English / German captions, 28 pages English / German text, 11 pages of scale drawings from all versions in 1:35 scale from John Rue, 14 camouflage schemes from Laurent Lecocq, graphics of tactical markings and table of organization of units using the Grille (Kriegstarke-Nachweisungen KStN).