Device has built-in battery. It charges via USB-C port. USB-C charging cable is included. There's also on/off switch and 2 LEDs: power and bluetooth status. Back cover is fastened with small Phillips screws, not glued to the case. This is great as I can later replace buil-in battery when it looses its capacity. Rotational angles, velocity, vibration frequency and displacement telemetry are streamed continuously from the device to connected smartphone. Ambient temperature, battery state and Bluetooth signal strength are also reported. Both Android and IOS are supported. Device is paired and bound via the app. You can bind multiple devices. App presents data in both tabular and graphical formats (scatter graphs). I am planning to use it with our new RC plane project that we are building with my son. Initially just to calibrate flaps, ailerons and rudder input limits and its central of mass distribution and bias if any (nose up or down during the flight). Later I want to figure out whether I can use WIT-Motion API to receive and process telemetry data outside of WIT-Motion Android app on my Ubuntu laptop for auxiliary remote real time feedback inputs into flight controls to enhance flight stability and correct navigation biases (persistent wind streams, ect). We also have Arduino based RC bot with ultrasonic radar sensor that may be controlled remotely by python script via Bluetooth connection. In addition we're planning to use it for in-house inertial navigation project with this bot.

Very sensitive and accurate modal vibration sensor capable of reporting in multiple vectors. The companion app is essential in communicating with the device and also serves in displaying results.

The module is a small, self powered little unit with just a power switch and two indicator LEDS.

Its rechargeable with the included cable.

The software is very basic but it works and records data.

I expected that it would display acceleration - it doesn't - but it shows velocity and displacement -

The frequency display is a little confusing but works -

The settings do allow control of the measurement period and frequency - allowing use down to "0 hertz" in the settings - Haven't played with it enough to see exactly how low it functions.

Overall, this is a lightweight, light duty device but its very simple to use and includes a lot of measurements - making it a really convenient tool for a very reasonable price.

For basic measurements and trouble shooting, its a useful tool to have on hand.

Software could use some work. Unit does work well once it is setup

I bought the WTVB01-BT50 model, which I thought would include a vibration (velocity) meter in my product. This module can measure vibration (Velocity and displacement) RMS in mm/s. However, the resolution of the velocity in mm/sec is an integer value of 1 mm/sec. It does not allow to obtain decimals, which is not very convenient when the readings want to compare with the ISO 10816 standard. To be professional equipment, the velocity measurement must be read with at least one decimal resolution, and two decimal places would be very convenient.
Could you improve the product by including in the speed at least one decimal resolution example in the range of 0.0 to 49.9 mm/sec or better, 0.00 "“ 49.99 mm/sec?