I know from experience that one of the most important survival resources is a good quality knife. It can assist in almost every survival related task. I found a great 5” Ka-Bar Brand knife designed to mount directly to a picatinny rail. The stock Mossberg shotgun does not have picatinny mounts so I purchased a barrel mount picatinny rail unit. This makes the knife easily accessible for quick deployment. A knife can perform 1000’s of survival tasks including dressing game, cutting wood and cordage, striking a fire steel, digging, scraping, prying, slicing and the list goes on and on. I prefer a larger survival knife but this one will work just fine. I sacrificed size for the seamless integrated mount option.