Factory Authorized replacement remote for CATX4, CATX50, CATXMT and many more see description for full list Brand new Original Equipment Authentic Part, Genuine Code Alarm Part Programming required - must have access to program button instructions included Will not replace CAT4 remote control even though it looks the same, please verify your part numbers and system before buying Thinner, Lighter, and Smaller than previous models, only requires one battery unlike previous models that require two Code Alarm OEM Authentic replacement remote control. This is a factory authorized replacement remote control for part numbers CATX4, CATXMT, CATXMLC (one way capability only), CATX50, CATX100, CATX1B (remote start capability only) and CATXTW (one way remote start capability only). Compatible systems are CA1050, CA1051, CA1053, CA1150, CA1151, CA1153, CA1550, CA1551, CA1553, CA2050, CA2051,CA5050, CA5051, CA5053, CA5054, CA5150, CA5152, CA5153, CA6150, CA6151, CA6153, CA6550, CA6552, CA6553. Additional compatible systems this remote will work on, but only provide start functionality are the CA4050, CA4051, CA4053, CA4054, CA4055. CA4552, CA4553, CA4554, CA4555. Programming is required, and access to the programming button is necessary, usually a dash mount button on most alarms/keyless entry systems, and on the antenna of remote start systems. This remote is thinner lighter and smaller than previous models, and only requires one battery, where the old ones require two. Any questions feel free to ask before buying. Please verify it will work for you, other remotes may look the same, but may not work. This will work on Code Alarm products only