Simple adapter (or thread reducer) that converts the common 3/8" male threads found on microphone mounts to a 1/4" male threads used by other devices such as LED ring lights. Mounting them on an arm gives you better control over lighting angles compared to mounting on the tripods they usually come with.

Take care when mounting devices onto the print because the threads can easily be sheared off. If the device you're mounting is heavy, consider buying a proper brass one such as the SmallRig ones instead.