The HPJ140 half portal with its characteristic half moon shape fits for existing swing doors or sliding doors. This interlock system has a reduced external volume meanwhile it creates a highly protected secure entrance. The APD ultrasonic sensors check if there is more than one person inside the portal, preventing the risk of tailgating. This security interlock system is also available in the versions approved to the LPS 1175: Issue 8 A1 (SR1), B3 (SR2) for resistance to attacks. It is also available in the RC3 and RC4 EN 1627 Attack Resistant versionsand in many other different versions.