The BK1856D Frequency Counter from B&K Precision is an economical and compact digital frequency counter which can measure frequencies from 0.1 Hz up to 3.5 GHz. It is an ideal frequency counter for benchtop radio frequency (RF) or audio applications. Features include 8 digits of resolution, 1 ppm accuracy, NIM/EURO BNC, External Clock In/Out, 1 Hz and 10 Hz resolution, and both positive and negative edge triggering. It is easy to use with push buttons, a 2.8 inch LCD display, and an auxiliary port for a PC connection, making it perfect for all levels of users. The BK1856D Frequency Counter is perfect for keeping your RF and audio frequencies in check.