Techniques and systems to monitor a blowout preventer. A device may include a protrusion sized to extend though an aperture of a blowout preventer. The device may also include a sensor disposed on a first end of the protrusion, wherein the sensor is configured to sense at least one condition occurring in a central bore of the blowout preventer disposed perpendicular to the aperture and generate a signal indicative of the sensed condition. The device may further include an electrical connector configured to receive the signal and transmit the signal from the device.