Made of high quality metal, durable and long lasting. Compact design, corrosion-resistant and wear-resistant. Removable adapter can fix the alarm and the adapter in advance. Simply plug into the bracket when it is in fishing position. Significantly reduce your preparation time. Specification: Color: Black Material: Metal Overall dimensions: Approx. 60 x 16 x 16 mm / 2.5 x 0.6 x 0.6inch Inner diameter of bite alarms thread: Approx. 8.40 mm / 0.33inch Diameter of the mounting thread: Approx. 9.10 mm / 0.36inch Whether removable: Yes Package Includes: 4 Pieces Quick Release Adapter for Bite Alarms Note: Please allow 1-3mm / 0.04-0.12inch error due to manual measurement. Thanks for your understanding.