70mai 4K A900 Ultra Review: Dual 4K Dash Cam Built on Twin Sony Starvis 2 Sensors

The bundle uses Sony Starvis 2 IMX678 sensors in both cameras, which TechRadar credits for delivering some of the crispest 4K footage in this segment of the dash camera market. The front unit has an f/1.8 lens that shoots 3840 x 2160P at 30fps, and the rear unit has an f/1.6 lens. The review's written description states the rear camera records the same 4K resolution at 25fps, while the specification list published with the same review gives 30fps for the rear unit; the two figures differ. Both cameras offer a 130-degree field of view, and HDR plus 70mai's Night Owl Vision 2.0 processing are applied to day and night recording.

The main camera is a compact box-shaped unit with a 3-inch rear-facing screen and four control buttons for adjusting settings and previewing footage. It carries a five-system GPS receiver and buffered emergency recording that saves up to three minutes and ten seconds before an incident and 30 seconds after it. Wi-Fi 6 handles file transfer at speeds of up to 45MBps, and storage is via microSD cards of up to 512GB, a ceiling the review lists among the product's drawbacks.

Several functions depend on accessories sold separately. Smart Parking Surveillance 2.0 requires hardwiring the camera into the vehicle; the same applies to around-the-clock monitoring. 4G Cloud+ 2.0 compatibility adds live view, remote playback and two-way voice communication. Driver Fatigue Alert and hands-free voice control are built in, and the unit uses supercapacitor technology rather than a battery for more durable operation across the temperature range inside a vehicle. 70mai's Battery Pack Mini, an optional extra, is described as providing backup power and up to 30 days of parking surveillance without draining the car's battery.

In the United States the 70mai 4K A900 Ultra is priced at $299.99 but was available from the US 70mai website for $239.99 at the time of writing. In the United Kingdom it is priced at £231, with the 70mai website offering it for £185 at the time of writing.

The front camera measures 3.62 x 2.36 x 2.02 inches, or 9.2 x 6.0 x 5.14 centimetres, and weighs 0.52 pounds, or 0.24 kilograms. The rear camera uses a conventional tube shape. Both attach to windscreen glass with supplied adhesive pads, and TechRadar says everything needed for installation is included in the box; the cameras can also run from a standard 12V in-car power socket using the supplied adapter. Among the review's criticisms are the amount of cabling that has to be fitted behind vehicle trim, the separate purchase required for the hardwire kit that unlocks the camera's additional features, and the Battery Pack Mini being an optional extra.