Feature:1. 20~75Hz Frequency meter, flame retardant, high durability and environmental protection, firm construction.2. Easy to identify the working state, having long life and low energy consumption, clear printing and high brightness.3. Dust can be effective prevented from getting into the indicator lamp interior due to the enclosed shell design.4. AD1622DHZ of the model, great for electricity, other equipment signal indicating and frequency displaying.5. Made of high strength plastic, has good impact resistance, more safe and convenient in usage and installation.Specification:Item Type: Frequency Indicator LightMaterial: Plastic Model: AD16-22DHZFrequency Range: 20~75Hz.Package List:1 x Indicator LightNote:Do not exceed the frequency range during installation.