I bought this compass because the magnetometer/compass in my phone is terrible and always gives incorrect readings. This is an ordinary magnetic/mechanical compass. It has the usual features, a cover that protects it and when raised gives you an aiming line and a few notches that can be used to find object sizes if you know its distance, or distance if you know its size - not a direct read, some mathematical work required for this, the numbers table included in the manual, can be copied into youSee full review