1: This base is used to set up a vehicle-mounted antenna 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) Color: As Shown Material: Aluminum Alloy Package Contents: 1 x 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.