Office or company building majority use card for opening doors.  And some use keys, pincodes and recently popular QR code.    

No matter a card, tag, key, pin or QR code, premises owner is not able to have full control of access right.  You may already realise keys can be used by someone that should not have access to your place.  Physical keys could be transferred or targeted to be stolen.  People may think dynamic QR code is safe, however, have you seem images or QR code being transferred real time on video conference software on FaceTime, Zoom, What'sApp, etc.,   

Proximity Card is nearly contactless when one awares of not touching in using a card. However, no-one would be able to avoid physical contact during key Issuing and recollection.   SARS Covid-19 is devastating and contactless to be everyone's choice in the semi-"META" world. 

Millions of door keys end up in landfills as a result of forgetful owners and new ownerships.  Plastic, heavy metal and hazardous material is not general recycled having great damage on Earth.  Some of your staffs might have many keys for Main entrance, Office door,  mailbox, locker, pedestal locks.  We should learn now what impact you can help to change for a green world with a little twist in practice. 

KiLax invents OPTIKI, a high security mobile access solutions using optical encrypted code works in all access system for commercial offices.  Digital transmitted key code can be used via mobile app or webpages.   Facilities owner and admin is capable to manage and monitor access from home and away.  Cloud based backbone empower unlimited system expansion for new locations, also, on-demand-access meeting facilities booking and share space is perfect with mobile access. Your first choice future proof all mobile access control.