Trinocular, for using a RPi CameraLook, I would only buy this one if you're planning to connect it to a C mount camera like the RPi HQ Camera. That combination works really well! I think most people are at least as happy with a binocular scope and a phone mount, but if you want to take long timelapses or leave a monitor set up as a magic window to a microscopic world, I get it. They're otherwise identical, and hey it's only money. Same Barlow lens options as the binocular version, 0.