Technical Specifications:

Voltage measurement range: AC 100-300V
Frequency measurement range: 10-100 Hz
Accuracy class: 0.1 (ensures very precise readings)
Display: Red LED display showing voltage, green display - frequency
Operating temperature: from -25°C to +55°C
Dimensions: 70 x 42 x 20 mm
Functions:

Two parameter display: Simultaneously shows both voltage (V) and frequency (Hz) values, allowing the user to monitor both readings without additional devices.
Red LED display: Bright LED display ensures easy visibility of readings under various lighting conditions, which is especially useful in industrial environments or low-light settings.
High precision: With an accuracy class of 0.1, this device provides reliable and accurate measurements, helping to avoid false readings and electrical system disruptions.
Usage:

In industrial facilities: Used for monitoring electrical network parameters in factories, workshops, and other industrial spaces to prevent voltage and frequency fluctuations that could cause equipment failures.
In electrical distribution networks: Helps ensure stable electricity supply by monitoring voltage and frequency deviations from the norm.
In laboratories and research facilities: Ideal for use during research or testing where precise voltage and frequency measurements are essential.
In home electrical installations: Used to accurately monitor voltage and frequency in households, especially where electrical fluctuations may occur.
Pros:

Two parameter display on one screen: Saves space and allows the user to see both main electrical network parameters at a glance.
High accuracy: Accuracy class 0.1 provides confidence that readings will be reliable and precise.
Wide measurement range: Measures both 100-300V voltage and 10-100 Hz frequency, making it suitable for various electrical network configurations.
Compact dimensions: Small size allows easy integration of the device into electrical panels or control boards.
Temperature resistance: Operates over a wide temperature range, making it suitable for various environments.
Cons:

Only for AC networks: The device measures only alternating current (AC) parameters and cannot be used in direct current (DC) networks.
Limited voltage range: The device is only suitable for the 100-300V range, so it cannot be applied in systems with higher or lower voltages.
Fixed color: The red LED display is highly visible, but some users may prefer LED colors other than red.
The voltage and frequency meter is a reliable and accurate tool designed for continuous monitoring of voltage and frequency in AC networks. It is well-suited for both industrial and laboratory conditions where reliable management of electrical parameters is important. The compact size and clear LED display make this meter easily adaptable for various needs, ensuring accurate and reliable results.