An ice screw is a device used to protect a climber when climbing on ice. Ice screws are tubular in shape. Common sizes and weights of ice screws are 12 to 22 centimetres in length, however shorter and longer screws can be found. Ice screws vary in weight by the size. Shorter ice screws are around 6.5 ounces, and the longer ice screws are about 8.5 ounces. When placing the screw in ice the tip is subjected to a lot of force. This dulls the tip over time. The newer, more modern ice screws often have replaceable tips. Some ice screws have a variety of features. Some have a separate crank for screwing the device into the ice, while others have an integrated handle and hangar. Attachments for clipping will either integrated into the crank design, or as a separate appendage to the screw.