I built mine very easily I just used a bucket with a lid. Drilled a couple holes in it ran the CO2 in hose to the bottom and sealed the hose to the lid. Ran a smaller vent hose at the top and sealed. This allows the CO2 to fill the bucket (CO2 is heavier than air) found a used CO2 bottle on craigslist and purchased a regulator. I set the regulator to run at about 5psi turn the gas on for about 5 min and return to some nice feeder who just went to sleep . Works like a champ the feeders all just look like the went to sleep they lay out very well for freezing and I know when they were frozen and how much they weigh. Makes it great for keeping track of who eats from what bag and nothing I have is every over 3-4 month in the freezer.