Transparent ruler for waveform measurement, capable of measuring frequency and amplitude. There is a slight scratch from around the 1.5cm mark to the 20Hz mark on the ruler. There is no problem with viewing (using) the markings. Also, because the material is plastic, there may be initial fine scratches. Please refrain from purchasing if you are concerned. - Brand: NIHON KOHDEN - Purpose: Waveform measurement ruler - Color: Transparent/Red - Features: Frequency and amplitude measurement possible - Scale: With Hz and mV markings - Condition: Almost unused Thank you for viewing.