Here's my open to tweaking "list"
Here's my take on the Gen 1 & 2 & 3 & "4"
LTI 20/20. Ancient. dates back to 1991
Kustom Pro Laser I ?
LTI Marksman similar to 20/20 scope improvements & software
Kustom Pro II (same as Pro I) w/ software enhancements
Stalker LIDAR this is a Gen 2 era but with Gen 3 engineering.
LTI UltraLyte ( I have busted one 2001) *** web site says 1997
Laser Atlanta R & S
Kustom Pro III
Most distance range finders came around 2003? & up. Osprey, Bushnell, Symmonds, etc.........
Kustom Pro Lite