1: This base is used to set up a vehicle-mounted antenna base outdoors 2: The standard ground grid recommends using 4 3.5-meter 0.5-2.5 square soft wires, and the enhanced ground grid can be matched according to the 1/4 wavelength of the used band (not included in the delivery list) The for -12 portable shortwave antenna only requires a basic M10 thread. Part name: MSK-04 antenna base for -12 Block M = SO239 Size: 7.3 x 3.9cm Model: MSK-04 for -12 Antenna interface: M female socket Feeder interface: M female socket Ground interface: M10 thread Standing wave: Less than 1.5 (ground installation matches the ground grid) Power tolerance: 200 for (FT8 100 forwatts) Weight: base is about 165g, Height: about 73mm (including M seat height) Diameter: about 39mm (excluding M female socket) Connection way: ANT end connects to the vehicle antenna, GND end is covered with ground grid and then screwed on the ground , after plugging into the ground, the ground grid is laid flat in 4 directions, and the M male feeder is used to connect the base. Please pay attention to the radio standing wave table when using (standing wave should be as Less than 1.8 as possible) (M10 thread interface) Color: silver Material: stainless steel Package Contents: 1 * MSK-04 antenna base (only includes antenna base, other accessories are not included) Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.