Umarex USA. Product Manuals A listing of Umarex airgun manuals sorted by brand. Click the link to download a PDF file of the manual. For the most current manual, please check the individual product page. Manuals - Walther Manual Listed is a softback owners manual for a Walther Auto Pistoll P 38,it is 8 1/2" by 6" 22 pages,well illustrated and is an original not a copy manual has some use wear and stains but is complete and great to have if you own this gun.