Specification】: 125KHz TK4100、EM4100 ID thin card, Pack of 40pcs.【Applicable scope】: Proximity Clamshell card works with the vast majority of access control systems.Cards are not compatible with UHF and / or encrypted readers like: HID, Cobra, APCiK, Paradox, Radio, Honeywell etc.【Coding details】: Pre-programmed with unique 18-digit ID number in each card.(The first 10 digitals are ABA code, the last 8 digitals are wiegand code).【Compatible】:Compatible with stand EM ID access devices or ID reader.【After-sale service】:If you have any questions, please contact us first, we will give you the best quality service.Professional after-sale technicians answer the problems in the development process for you in time.