7 Watch Case Opening Knives For Opening Tight Case Backs. This is a new set of 7 watch case opening knives. Great for opening water proof and press on watch backs. You receive: One long handle stainless steel knife that measures approximately 6 1/4" (158 mm) long. One steel knife that measures approximately 5 1/4" (133 mm) long. One steel knife that measures approximately 5 1/8" (130 mm) long. One steel knife with a blue sleeve that measures approximately 4 1/8" (104 mm) long. One steel knife with a blue sleeve that measures approximately 5 1/8" (130 mm) long. One bench knife with a wooden handle that measures approximately 4 5/8" (116 mm) long. One knife with a round wooden handle that measures approximately 6" (152 mm) long. We work hard to update our descriptions and pictures of our merchandise. As part of a process of ongoing innovation by our suppliers, newer versions of the item shown may be shipped before we are able to complete an update. As a result there may be a slight variation in color and design.