A balun (from "balanced to unbalanced", originally, is an electrical device that allows balanced and unbalanced lines to be interfaced without disturbing the impedance arrangement of either line.
 
This is a handy device for portable or tempoary antenna installations - This is a long wire version - see other sale for dipole.
 
You'll need two lengths of wire that attach on the nut & bolts. The one on the side is the earth/ground connection and the one on the end is the signal/feed line from teh transmitter; the balun will allow a match to a 50 Ohms cable / Transceiver.
 
Balun operating power up to 100W SSB Suitable HF Shortwave Antennas between frequency of 3-30mhz ideal for outdoor activations / Portable QRP Stations (Beware of using high power/continuous transmissions with data modes such as FT8 due to heating of the core resulting in high SWR).
 
Good for matching antenna to receiver only equipment as well - may inporove received signal as it will allow maximum power transfer (maximum received signal) to be transferred from the antenna to the receiving equipment.  May help reduce noise from fed line pickup.
 
This little Balun is light -  only 50g and case is accessible for modification or repair.  Also allows for waterproofing if required.
 
Product size: 91x36x26MM/3.58x1.42x1.02inch including terminal
housing size: 61x36x26MM/2.4x1.42x1.02inch
 
I will ship this with the lid off the package - to reduce height for shipping - just clip it back on when you receive it.