The structure of this lens base is simple, and it can be installed quickly by fixing it with screws. The lens base can be used to hold and fix the helmet lens and allows the lens to move up and down. It is made of ABS material, which is lightweight and durable. The length of type A is 10cm, the width is 4cm, the height is 1cm; the length of type B is 8cm, the width is 3.2cm, the height is 1cm. The type A is suitable for AGV K3 K4, the type B is suitable for AGV K1 K3SV K5. Item Name: Helmet Visor Base Material: ABS Size Details: Size: A: 10cm x 4cm x 1cm/3.94" x 1.57" x 0.39" (Approx.) B: 8cm x 3.2cm x 1cm/3.15" x 1.26" x 0.39" (Approx.) Notes: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement. Package Includes: 2 x Shield Gear Plates 4 x Screws Note: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement.