The Technics SL-J2 is a quartz-controlled direct-drive fully automatic turntable system produced by Technics between 1984 and 1988. It features a linear tracking tonearm with an optical sensor that allows for the kind of track-skipping more typical of CD players. The sensor also detects the size of the record sitting on the platter (7-inch, 10-inch, or 12-inch), which allows the needle to drop precisely on the first track.