This is a super cool model 709U Volcano lava lamp. It’s a plastic lamp that is suppose to change from red to blue light but the red bulb is out and only the blue light is working. Maybe the red light can be replaced?
It otherwise works great if you don’t mind the pause in light when it’s suppose to be the red light.
There is a tiny on/off switch is at the base near the cord.
Let me know if you have any questions!