This product is made to mount the DJI O4 Pro FPV camera to your drone. It mounts to your front standoffs. The DJI O4 Pro camera is 20mm wide so it will only fit between standoff that are 27mm from center to center in width or larger. We positioned the camera as far forward as we can without having the camera stick out to far or having to much frame in view at higher angles. Please choose your standoff width from the drop down menu on this product page. This measurement is the center of your standoff to the center of the other standoff used for mounting. This is NOT the inner distance between the standoffs. Please bolt the camera to the TPU mount first. Then slide the TPU onto the standoffs. These mounts are made only for 5mm knurled standoffs. Enjoy!!