All AEI tags that are re-used are to be pressure tested to determine if they have any leaks. The AI2200-650 Tag Pressure Testing Cabinet is used to leak test used AEI tags so that they conform to the requirements found in Paragraph 10.4 in the Association of american Railroads' Standard for Automatic Equipment Identification S-918 Version 1.1. A copy of this paragraph can be downloaded from http://www.signalcc.com/aei/S-918-10-4.pdf. Please note that you must provide an external source of air pressure to this device. A pressure regulator is included with the unit. For more information on using the Tag pressure Testing Cabinet, please click on the "Download" button below. (AP200-650)$1,500.00 Tag Pressure Testing Cabinet Instructions