137 Mhz V-DIPOLE Antenna Support.
This is a simple part that holds a pair of 4 mm aluminium rods at exactly 120°. There are 4 cut-outs for 3mm cable ties which hold the antenna in place, and an arrow to line up with a compass.
Based on a design by Adam -
https://www.rtl-sdr.com/simple-noaameteor-weather-satellite-antenna-137-mhz-v-dipole/