Two 'Northstar V1' circular subdermal implants each containing five red LEDs, processor and battery. When operating, the LEDs turned on in the presence of a magnetic field.
The implant marked 'Northstar P1' is the earlier version of the design. This device was implanted in an unknown person in 2015-2016.
The implant marked 'Grindhouse V1 P2' with the pentagram background is the later version, which was redesigned to address issues with locking during immersion testing, This device was implanted in Jes Waldrip in 2015 and remained there for around eight months.