43mm length tube is suitable for 2-4in compact speaker. 93mm length tube is suitable for 5-6.5in compact speaker. 105mm length tube is suitable for 8in compact speaker. 123mm length tube is suitable for 8in compact speaker. Made of high quality ABS plastic, this product is sturdy and durable. The speaker port, also known as the sound tube and the air hole, is often used in the ported speaker. It mainly suppresses the airflow sound of the speaker in the box and overlaps the sound pressure radiated in front of the speaker to produce a bass effect. Specifications: Material:ABS Color:Black Length:43mm/1.7in,93mm/3.66in,105mm/4.13in,123mm/4.84in,(Optional) Note: Please allow 1-2cm errors due to manual measurement,pls make sure that you do not mind before you order. Due to the difference between different monitors, the picture may not reflect the actual color of the item. Package Includes: 2x Speaker Inverter Tubes When shopping, please pay attention to the size and dimensions of the product to ensure that it meets your needs. In the title and , we have provided detailed information about the product, including its features and specifications We want you to be completely satisfied with your purchase, so if you have any questions or concerns, please don''''t hesitate to contact us. We are here to help and will do our best to assist you. Thank you for choosing our product. We hope you enjoy it