Simple Spring Antenna - 433MHz

via Adafruit
$1.93
SKU AF-4394

This simple spring antenna matches great with any of our 433MHz RFM and LoRa breakouts, bonnets and Feathers. They're made of copper-clad wire so you can solder them easily.

They are compact, only  ~38mm / 1.5" long, and have 2.5dBi of gain and 50Ω impedance, so it will work fantastically with just about any 400~450MHz wireless receiver/transmitter.