COMMON FORMAT: 25 Prox 26 Bit Keyfobs 125khz access control Proximity Key Fobs formatted with the 26-bit H10301 standard format used on most access control security systems. | APPEARANCE: 30mm x 37mm x 5mm Gray keyless entry Key Fobs | SITE CODE: These RFID access control KeyTags come in the site code 98 | COMPATIBLE: These isoprox compatible contactless Keyfobs work with the same 26 bit weigand readers that both the 1386 ISOProx and 1326 ISOProx key cards work with. Compatible 125khz card readers include: Proxpoint Plus, Thinline II, MiniProx, RP40, RP10, RPK40, RP15, Prox80, ProxPro, EntryProx 4045, Bosch ARD-AYJ12, Viking PRX-2, and many more. | Before Purchase Considerations 1. These fobs are not the iClass format and will NOT work with iClass card readers. 2. These fobs have a site code of 100. If you are already using a different site code, you will need to check with your access control system supplier to confirm that your system will accept multiple site codes. 3. If you are unsure if your system will accept our fobs, contact us through Amazon and we will research your system and let you know if our fobs will work on your system. Here are our troubleshooting steps to help after they have made the purchase After Purchase Technical Support If our fobs are not working with your system, contact us through Amazon and provide the following information. 1. The access control system you are using including the version of software that you are running. 2. The make and model of card reader you are using. We will respond back and tell you if our fobs will work with your system or not. If they will, we will try and provide steps to help you get your fobs working.