Manfrotto MVA50A Fluid Base with Retractable Feet Description. The Fluid Monopod base is a Manfrotto first featuring a patented system which uses a fluid cartridge giving incredibly smooth panning action to the monopod when shooting video. It enables judder-free panoramic rotation that cannot be achieved with regular monopods. The retractable feet provide the necessary stability for fluid panning & enable the correct tilt position to be reached on the most uneven surfaces. This means users can take advantage of pan fluidity in multiple conditions. MVA50A can be easily attached on the last section of photo monopods & it is suitable for use with 679B 680B All monopods featuring a 20mm tube in the bottom section i. e.558B