This oscilloscope is a Type 561A, made in the US by Tektronix Inc around 1969. It is an indicator unit with provision for two plug-in units. The plug-in unit on the right controls the horizontal deflection on the oscilloscope's screen while the left plug-in unit controls the vertical deflection. There are a number of plug in units that could be chosen from any of Tektronix series 2 or series 3 groups. The user would choose the plug-ins that best suited their use.This particular oscilloscope uses a type 3A1 plug-in on the left and a 3B4 on the right. The plug-ins could also control input impedance, sweep rates, risetime and bandpass. While the main unit also has controls that affect the display on its front and back panels, the major characteristics are controlled by the plug in units.

The Oscilloscope has an 8x10cm display screen and a solid state. When operating the oscilloscope it is important to ensure that the air can flow freely around the instrument, helping it remain cool. The vacuum tubes should not be operated at temperatures above 150 °C if the room temperature is at 25 °C or 175 °C if the room temperature is at 50 °C. If the oscilloscope overheats there is a thermal cutout that turns off the power.

The cathode ray tube in this oscilloscope is a Type T561 with a rectangular ceramic envelope. It has an accelerating potential of 3.5 kv.