This is a shorting bar that grounds utility 240VAC aerial cables to the ground. Spare operator required per use.
It also acts as an adjustable, rotary V dipole, based on two alix telescopic verticals.
It should be extensible, but we never used it beyond 10m so far. Based on an idea by @yo9lig
@yo3gnd nice build! Made something similar. Works quite well from 10 to 20M Band.
@DG1JAN You can see the workmanship in yours, between planning and making something ad-hoc like I did. Nice design!