We use this as a lid over a trash bag lined 5 gallon bucket for our dog poop trash. We use 8 gallon heavy duty bags, double sacked, and as we scoop we cover each new layer with kitty litter. We empty it once a week for trash day. This has worked out excellent for us. The only problem we have had is rain water leaking in when we untwist to open. Now we just pull the whole lid off and it doesn’t leak because the twist seal hasn’t been broken. These lids are great quality and serve their purpose. Our local farm supply store sells them but I like the convenience of Amazon.I saw a few reviews which said they had difficulty getting the rim/lid onto the bucket; I did not find that to be the case. The rims snapped right on, and fit perfectly, and I had no problem getting the lid to spin close. My buckets are inside, so I haven't tested the airtightness or leak protection, but the product was EXACTLY what I expected, and I am happy with it.I ordered 10 lids. The first delivery was 4 lids, all packaged in separate boxes that could have easily held 4 lids. The next day 5 more lids were delivered, also in separate boxes. I'm still waiting on delivery of the last lid. "Updated" The order was finalized. These black "pet food" lids appear to be made just like the white "food" storage lids that I paid a third more for from another seller. I paired them with $5 harbor freight buckets to use for storage.Bought this to put on a 5 gallon bucket full of pellets for our smoker. Works great. Easy to spin the lid off and on, but seals tight to keep everything fresh. Very happy with the purchase.Snapped onto the buckets I bought at the hardware store. Seal well. Storing rolled oats and steel cut oats.My only issue with Gamma lids is hoe hard they are to get on buckets. However, once they are on, that's it. Nothing is getting past them.These worked perfectly for storing the bird seed and suet in our garage. Keeps little critters (mice) away and the food dry -- all we can really ask for.I would have given this 5 stars had it not been so difficult to get the base ring on the bucket. I almost returned them because they didn't seem to fit on any buckets I tried. I decided to get aggressive and use a rubber mallet and pound it on. That seemed to work. Time will tell if the stress on the bucket eventually ends up cracking it.TO INSTALL:1. Make sure the o ring is pushed as far back into the lid groove before putting it on to the pail.2. Take apart the lid into it's two components: i) outer ringii) screw on lid top.3. Put the outer ring on the pail and push down hard all the way around until it is properly seated. remember this is an airtight seal so if you are trying to put it on to the pail with the two components still together you are fighting air pressure unnecessarily.4. Now you can easily screw the top on and off the pail.* If you found this helpful please let Amazon know, thanks.Great for adding a leakproof sealing lid to any standard 5 gallon pail. Most lids that make a good seal are difficult to remove, the gamma seal lids are simple twist open / close. I found this works with most 3.5 and 7 gallon pails as long as the OD of the lid is 11.75”.The various colours make organizing contents by colour easy.Great for emergency applications where you don’t want to have trouble opening up the lid .As a large family, we buy many dry items in bulk. After seeing "gamma lids" recommended online, I bought one and a "Meguiars" 5 gallon bucket to use it with (also available on Amazon). The lid is tricky to install, but there are heaps of YouTube videos to point you in the right direction. I have 3 of these buckets and lids now to store my bulk flour, rice, and diatomaceous earth in. My older kids can easily open them, but the tiny one can't - so that's a win! We really like them.It's really hard to install the ring on the bucket. I had to put the bucket up side down and step really hard on the bucket. With my height and weight stepping on the plastic bucket to clip the ring was not reassuring. But once it's done the lid is really easy to close and open. The lid has a rubber-like seal around it. The product is sturdy and I think will last.I'm using these to store my 3D printer filaments rolls in a dry environment.I do recommend this product. Better make sure you have someone to help you clip the ring on the installation.If you like my review please hit the HELPFUL button.Got these to fit 25 Litre Plastic Bucket with LID... https://www.amazon.co.uk/dp/B00ECVX1NQ?ref=ppx_pop_mob_ap_shareBut does not fit not wide enough. Down to me not checking.Overall a good product but am now using car wash buckets that are well Leary.Product seems well made but doesn’t fit the bucket I bought ,even though it was in the perameter of the sizing. Quite expensive too...Be better if they could recommend a 20 Litre bucket it would work with.