A panel where operator control back pressure applied on a closed well to keep the well under control (Keep Bottom hole pressure constant).
It has many components as shown in the picture:
1- Control lever: choke on the well using hydraulic choke (need air supply to function)
2- Choke position indicator: indicates choke opening %.
3- Pressure gauges: Read pressures on string & annulus sides.
4- Hydraulic Regulator: Control speed of choke opening and closing.
5- Pump Stroke/meter counter: Indicate counter strokes pumped while killing operation, and flow rate from each mud pump.
6- Hydraulic pump,reservoir and hand pump: to operate the control lever in case of air supply failure.