Built of aluminum, the ChokeRing B3/E6 is a high precision multi-frequency antenna for reference stations. It is recognized for its durability in harsh conditions and reliability. Featuring low-noise amplifiers, the ChokeRing B3/E6 is enabled for multi-frequency reception (GPS, GLONASS and Galileo) and to mitigate multipath by attenuating reflected GPS signals thus significantly improving the reliability and accuracy of your reading.