The sleeve is designed both guy the mast and attach antenna wires. The sleeve sticks to the DXWire mini GFK mast (10m) at around 5m, so the vertical λ/4 part of the antenna fits to the aligns part of the mast. The rim is used to attach the radials, which can be used simultaneously as guying ropes when the DXWire UL wire or a similarly strong wire is used. Using 3 radials at 45 degrees vertical, the foot point resistance matches 50 Ohm, so the coax can be directly connected and no additional balun or matching is needed. The tuned wire lengths are documented in the attached PDF.
The antenna was calculated based on https://m0ukd.com/calculators/quarter-wave-ground-plane-antenna-calculator/
The author marked this model as their own original creation.