Ring Video Doorbell 4 launches on May 5 for $199

Ring introduces a new video doorbell that can be wired or battery operated. The Video Doorbell 4 features a 1080p camera, motion detection and pre-roll technology, which allows users to see four seconds of color image when moving.

The Video Doorbell 3 that appeared last year also has the Pre-Roll function, but that video doorbell is about images in black and white, while the new model displays those images in color.

The function displays four seconds of an image of the moment before a movement is detected. This works by continuously recording a buffer and saving it at the moment of motion detection. In this way the previous seconds can be recorded.

The Video Doorbell 4 also has similar features to its predecessor. The camera sensor has a 1080p resolution and there are a speaker and microphone. The new video doorbell is battery powered, but can also be wired. The device supports WiFi on 2.4GHz and 5GHz. Amazon subsidiary Ring will start selling the new model on May 5.