Old ATX DVR with plastic cameras. While this ATX school bus camera or vehicle passenger camera surveillance system DVR lock box was small at the time it was produced, it is now one of the largest in comparison to the new generation of the school bus video or vehicle camera systems DVRs now designated the "SD4m" mini series, which is now about 1/8 the size of the pictured ATX DVR lockbox.

Whether it involves low cost affordable school bus cameras, digital bus video cameras, vehicle camera, mobile video surveillance systems, digital in-car video cameras, in-car cameras, bus camera surveillance, it is always best to invest in 100% Solid State digital like the SD4FH series, small DVR mountable under dash where it will not present a hazard to the driver or children.

Medicaid Medical Transport In-Vehicle Cameras Surveillance applications are similar in that they have very limited mounting locations for the DVRs.
https://vehiclevideocameras.com/mobile-video-applications/non-emergency-medical-trans

As the size of the DVRs for these school bus camera systems became smaller, the applications became more usable in other vehicle types. For example, the: 5th Wheel King Pin Trailer CS1 Spotter Yard Mule Camera systems are now equipped in terminal warehouse yard tractors operated by yard jockeys, swapping trailers from place to place for loading and unloading, which has become more prevalent.

The same can be said of the Forklift HD Industrial Operator Safety Camera System applications as these vehicles have limited places other than mounting these vehicle video camera systems, so the smaller the components, the easier it is to use them in these other applications.