Super Antenna TH1 Thumb Screw for MP1 Antenna THIS IS: The model TH1 Thumb Screw for the Super Antenna MP1 Antenna. It holds the SuperSlider coil locked in position for mobile operation. COMPATIBILITY: This TH1 ThumbScrew fits all models of MP1 Super Antennas (old and new versions). THREAD SIZE: 1/4"-20. THREAD LENGTH: 0.25" (a quarter inch). SCREW MATERIAL: Nylon. INCLUDES RUBBER WASHER. ENGINEERING: Each black polymer bat handle thumbscrew is engineered from 2 different component parts, providing a smooth non-destructive nylon screw and low profile tough black polymer handle that fits flat to the body of the SuperSlider. It is also called a wingnut or plastic wing-screw. WEIGHT: 0.1 ounce. DIRECT REPLACEMENT FOR MP1: Series Super Antenna MP1 antennas, SuperStick, SuperWhip, SuperSlider. SPARE PART for MP1 series. NOTE: THIS IS NOT AN ANTENNA, THIS IS A THUMB SCREW.