Counter - TOOGOO (R) 50 MHz Crystal Oscillator Frequency counter Testers DIY Kit 5 Resolution Digital Red Color: Red, Simple Construction , compact design, easy to install and debug. Designed to measure the frequency of oscillation of most crystal oscillators. Based on PIC microcontroller can measure the frequency of 1 Hz to 50 MHz. Five digits of precision, for example kHz x.xxxx, MHz or xx.xxx x.xxxx MHz. General for feeding USB interface can be used for power supply, AC adapter or a battery of 9 V can be used too, it is used.