The automotive industry has standardized on power levels and are well known across the industry. With the advent of battery powered cars and hybrid ones added to the already present, Petrol and Diesel version, these power levels have remained unchanged for now. Reed Switches perform exceptionally well at low loads and consequently meet a high number of operations in the field. Molded and encapsulated reed sensors are specially manufactured to withstand shock and extremes of temperature and humidity that are required to be met in automotive applications. We have suggested recommended products for use in each application, but this does not mean that the other products in the same product category will be unsuitable. We have also classified individual applications into types and these guidelines will help select the right magnetic sensitivity and type of magnet to use from our range of products.