AXIS TS3901 Rail Extensions allow AXIS S3016 Recorder to be mounted in deep server racks with a post to post distance between 499mm (19.6in) and 690mm (27.1in). No rails extensions are needed for a post to post distance between 376mm (14.8in) and 499mm (19.6in). Each rail extension is composed of two parts which replace two segments of the original rails provided with AXIS S3016 Recorder.