Here is the proximity reader for a Paxton Switch2 access control system we installed recently. They have many other styles of reader/keypads available.
Switch2 is more suitable for external use than the Compact system. This is because the Switch2 control unit is mounted inside the building, rather than being in the reader/keypad itself as in the Compact. Therefore Compact systems are normally only fitted internally.
If you need audit-trail, time-sheets, anti-passback etc, then look at the Paxton Net2 or 10 systems