I found a Te-175 with 2 tanks on Ebay for 500$.. Closed loop, passive, no pump.. I put one empty tank in my small freezer, empty the other tank in the top of the extractor.. In a couple of hours, the butane has condensed back into the tank in the freezer.. Now I get to use it again.. It's a small extractor, only 60 grams at a time.. Also bought the heating pad for the vacuum pot.. Only took me one time blasting to decide that wasn't for me.. I can do a 1/4lb in 2 runs.. I don't remove the oil from the first run to do the second. I usually don't sell, but I did to pay for it.. That took a day..