4.5 Inch Closed Black Tactical Rescue Spring Assist Knife - Tophatter's Inc. Weapons Store OnlineMtech USA 4. 7 Inch Closed Length Spring Assisted Knife. Stainless Steel Blade. Black Aluminum Handle. Includes Pocket clip Features Spring assisted knife 3. 5'''' 2. 8mm thick blade, stainless steel Black blade 4. 5'''' closed Black anodized aluminum handle Includes pocket clip, seat belt cutter & glass breaker Opening is the same as regular folder, but once the opening process is manually started, then the Internal Spring Kicks in, and helps to