Files with h3r file extension can be usually found as video recordings made in some older security cameras from Panasonic.
H3R file extension - Panasonic camera security recording
What is h3r file? How to open h3r files?
File type specification:
The h3r file extension seems to be mainly related to some old product line of Panasonic's security cameras and used for some kind of video recording.
The h3r file contains high-compressed video captured by the Panasonic camera.