Use this mount for your DJI O3 Air unit VTX. Ideal for hobbyists and FPV enthusiasts. The mount size is 30x30mm or 20x20mm. It has dimensions of H:20mm L:38mm W:38mm. Comes with 1x RDQ DJI O3 Unit 30x30 / 20x20 Mount Adapter - 3D Printed TPU. For 30x30 mounting, you need 4x M3 hex nuts and for 20x20 mounting, 4x M2 hex nuts.