The Gibraltar SC-4402 Bass Drum Anchor is a practical Bass Drum anchor that is mounted on the reso tension tire of the Bass Drum. The two spikes effectively prevent the bass drum from slipping away during play. The spikes are rotatable and have one metal and one plastic side. If the Bass Drum is placed on a carpet, it is recommended to use the metal side, the plastic side is suitable for harder floors, such as wood for example.