4 New Pocket Watch Screw Back Case Openers. Vacuum Case Opener. This is a new vacuum case opener. It is made of rubber and fits in the palm of your hand. This opener was designed for opening pocket watch cases. New Case Knife. This is a new case knife. Configured to make opening certain cases easier, this opener is popular among many watchmakers. Simply place the blade under the case back and twist. It measures approximately 3" (76 mm). Mold Cutting Knife Handles. This is a new set of 2 mold cutting handles. Each is used for #11 and #12 blades. These are excellent for cutting rubber molds and wax carving. You receive: One stainless steel cutting knife handle measuring approximately 4 3/4" (121 mm). One stainless steel cutting knife with a plastic handle measuring approximately 5" (127 mm).