The ETH-300 Series features model numbers that reflect angle accuracy and have common features. All models have dual displays, and a detachable tribrach.

The ETH-302 has 2" accuracy, ETH-305 has 5" , the ETH-310 has 10" , and the ETH-320 has 20" angle accuracy. The ETH-302 and ETH-305 are equipped with compensator.

Horizontal and vertical angles can be observed simultaneously on the large 2 line, back-lit LCD displays, and vertical angles can be easily converted to percent slope with one key stroke. Other standard features include a horizontal angle zero set, automatic power off to conserve batteries, and a battery life indicator on the LCD display. Four AA alkaline batteries provide 25 - 28 hours of continuous operation.