The Tektronix 316 is a three-inch scope introduced in 1959, similar to the 317. The main difference is that the 317 has more CRT accelerating voltage for a brighter, sharp display. The 316 has a portable benchtop shape. The scope was also made in two other forms, the RM16 and the RS16. The RM16 is a rackmount version of the 316. The RS16 is also a rackmount version of the 316, but has the power supply in a separate unit so it can fit in shallow racks.