Cheap 40m laser rangefinder working principle

[Axk]

How does a rangefinder like this work?

https://www.aliexpress.com/item/S7-Mileseey-s7-laser-distance-meter-40m-60m-80m-100m-Mini-Handheld-optical-laser-Rangefinder-binoculars/32859078717.html?spm=a2g0v.10010108.1000001.11.5d974ed2JxQNOC

Is it just time of flight?
Multiple frequency phase-shift?

What frequencies are we talking about roughly?

[Axk]

Found a good reverse-engineering article (in Russian): https://habr.com/ru/post/327642/

[German_EE]

For those of you who cannot read Russian:

The range finder contains two VHF oscillators separated by a few KHz. The first oscillator modulates the laser beam before it is transmitted and the second oscillator is mixed with the incoming signal. The difference between the received signal modulation frequency and the reference will not vary (unless either the instrument or the target is moving) but there will be a phase difference between the two. The phase difference varies according to distance, this is measured and converted into feet/meters/yards by the CPU before feeding the number to the display.