A 1:1 "micro" Balun for use on HF (best suited for 7-30MHz) for when you're out portable or need a low-impact balun solution. Although small, it's light enough to mount on a fishing-pole but still able to operate at up to 100w under most conditions. As it's a Choke Balun, it can also be used with a Doublet/G5RV at the ladder-line/coax junction and even at the feedpoint of a resonant vertical.
All fixings are stainless-steel and we now include a pair of wing-nuts if you prefer "quick-release" Hamming.
2nd picture shows our prototype with the terminals at the top of the box and an Elecraft KX3 for scale - yes, the box is small!