Yes, our collars can be used with any standard Airtag holder provided by a 3rd party seller as long as the holder's specs indicate that it will fit a 1/2" wide collar. (In fact, the owner of Made By Cleo uses an Airtag with their MBC collars to keep track of their indoor/outdoor kitty when he's outside). Virtually all of the smallest or small pet-sized Airtag holders will fit a 1/2" collar. We have not found any options on the market (yet) that are limited to only fitting a collar narrower than ours. With that said, please always look for the product details before purchasing your Airtag holder, to ensure it will fit 1/2" collars.Please note that Airtags or Airtag holders are not sold in our store but can be purchased at many online retailers. Made By Cleo is not responsible for the loss of your pet's Airtag, if he or she should lose their collar. Airtags are a very helpful technology for some specific contexts, like knowing whether or not your pet is in close range of your home or in a specific part of your home. However, they are far from perfect if you are intending for the Airtag to provide constant realtime data about the exact location of your pet. Also, Airtags are still susceptible to being lost, especially if your pet's collar has a breakaway buckle on it, which increases the chance of your pet losing the collar outside (even though we still strongly recommend using only breakaway collars for cats who go outside). If your home is in a densely populated area with a lot of people using Apple devices, you're in luck and will probably have a lot more success in locating the lost pet, or lost collar that has the Airtag attached to it. However, if you live in a more spread-out, rural area or even in a regular city neighborhood, there will likely be a lot of patchiness in terms of locations of Apple devices around you vs. (Android) to help your app locate the Airtag. For this reason, it's still possible to lose an Airtag (and anything or pet attached to the Airtag). Please read up on the technology before purchasing to ensure it's a good fit for you!