Features: This is a bass coil positioning gauge and also repair parts for a bass coil. It can be used for the maintenance of speaker bass coil. Not a disposable product, can be used repeatedly. Each batch is different, the color is different, but it does not affect the use. Please check the size carefully; if the size does not match, the buyer is responsible for return shipping. Magnetic circuit gauge, voice coil gauge, magnet gauge – these three products are different and cannot be used interchangeably. Note: Color is random. Specifications: Material: ABS Size: 19mm / 25mm/35mm/38mm/50mm/65mm/75mm/100mm/13mm/14mm Optional Type: Type A; Type B; Type C; Type D; Type E; Type F; Type G; Type H; Type I; Type J; Type K; Type L; Type M; Type N; Type O; Type P; Note: Please allow 1-2 cm error due to manual measurement, please ensure you don't mind before ordering. Due to the difference between different monitors, the picture may not reflect the actual color of the item. Package Includes: 1x Speaker Voice Coil Positioning Gauge (Random Color)