If you're doing network training, you can't really observe collisions on a modern switch. You need a hub for that.
Well I'm here to help with this two-speed technological marvel. Comes with 8 ports of unavoidable bit smashing collisions for your packet capturing thrills and chills..
Cash, or will trade for a 10W+ solar panel, a bunch of harvested 18650s, CO2 laser lenses, (censored), usual stuff like that.