After some research and looking a more than a few websites (o'kief, aqua labs, trim scene) I purchased a tumbler from Easy-Kief. It is put together very well, is easy to operate and has a supported motor and poly screen. I froze about 250 grams of trim for the first test run and was amazed at the amount of Kief I got. I have found that the first 20 minutes is going to yield the A grade. You will still get the Kief even after a 40 minute or longer run. I found that it all depends on the quality/quanity/dryness and how fast the tumbled product breaks down. Great tumbler at a good price.

www.easykief.com