Arkon's PPTAB192L23 portable mobile printer seat rail mount is ideal for holding portable mobile printers, including those from Zebra, Epson, and Brother in your car or truck. The seat rail mount is made of strong yet flexible aluminum, and is ideal for service vehicles, trucks, or those who want easy access to their device but prefer mounting it somewhere other than the windshield or dash. Use a socket wrench to install the mount to the car's seat rail. Loosen the passenger seat track bolt, insert one of the included seat track bolt brackets, and then retighten the bolt. The seat bolt bracket openings measure 12mm wide and 30mm long. Bend the 23'' gooseneck and rotate the swivel ball adapter head for 360-degree rotation for exact positioning of the device. The mount's holder features a spring-loaded design that makes it easy to insert or remove the printer by pushing down on the lower legs of the holder with one hand. Included with the holder are 4 support legs (2 short and 2 long versions) made especially for holding mobile printers. Choose the 4 legs that provide the best fit for your portable mobile printer. These insert at the top and bottom of the holder and can be easily adjusted in order to keep any side buttons and ports unobstructed. The holder can also fit large tablets with 7''-18.4'' screen size by switching out the printer support legs for the tablet support legs that are also included. Note: some mobile printers may need a combination of printer and tablet legs for best fit.