Works well actually, just with the cooling unit. I didn’t read the description that clearly says you use it with the cooling unit so I was expecting it to be like the TM 3-d cooling stem w the basket packing. This works much better than the 50/80mm tube stems from TM.com or the GravLabs taster. WPA side serves as nice wide mouthpiece, and WPA obviously. It cools well even with the cooling until disassembled, or even with 3/4mm boro balls in between the cooling unit ends with the nuts and bolts removed. Well worth the 20 bucks.