Are they swingarm spools or axle sliders? Well they are both really!! The spool is mounted to a special, black-anodized aluminum bracket (included with the kit). The product will give protection to the rear axle and swingarm area in a crash. When not protecting your investment the "cotton reel" can be used to lift the motorcycle using a rear stand with hooks. For rear wheel removal, you can take the Cotton Reels out of the aluminum blocks and insert them into the paddock stand bobbin screw holes.