not very big but has little spike on the bottom of the last bulb thats heading straight up for the sky..he lives in a glass jar too...I got them at the dollar store for well a dollar and bought all 15 of them for my windows and to give the plants some needed local humidity..The lava rocks get warmed in the east window, the sphagnum sweats and makes water inside, then the clay picks up the water and transfers it to the plant in the net basket
you can see it stays so warm in the jar the sphagnum is coming back to life too