Mount thisZoom GearfromFantasea Lineonto the zoom ring of the Sony E PZ 16-50mm f/3.5-5.6 OSS Lens, in order to adjust the focal length when the lens is inside the FML Flat Port 34. This port is compatible with Fantasea underwater camera housings that have FML mounts, including the FA6500 enclosure for Sony’s Alpha a6500 and a6300 models. The gear connects to the housing’s lens dial, which can be turned for a smooth, seamless operation of the 16-50mm’s zoom function. Power zoom is inaccessible when using this gear.