It generally contains a thin wire (sometimes made inside porcelain) which melts and breaks the circuit when heated by a current higher than that the circuit is rated for. Using fuse wire of a higher rating is extremely dangerous. Automotive fuses are a segment of fuses which are used to protect the wiring and electrical equipments of the vehicle. These generally don’t cross the 24 volts direct current but some are rated for a 42 – volt electrical system. The fuses of five types Bosch type, Lucas type, Glass tube type and Limiter type. These types of fuses come in six different types of physical dimensions: micro2, micro3, low-profile mini (APS), mini (APM / ATM), regular (APR / ATC / ATO) and maxi (APX) heavy-duty. Color coding is used in fuses like a common coloring scheme is used in blade fuses for the micro2, micro3, low-profile mini, mini, and regular size fuses, and a partial color similarity with the maxi size fuses. Fuses are generally used for non – automotive purposes. The regular blade – type fuses, also known as standard fuses were developed in 1976 for low – voltages use in motor vehicles whereas the mini fuses were developed in the 1990s. Blade type fuses can be mounted inside the fuse blocks, in – line fuse holders, or fuse clips. The ATC fuse has a fuse element which is closed or sealed inside a plastic housing and the ATO fuse has a fuse element which is open or shown on the bottom of the fuse between the blades. Every fuse is printed with the rated current in amperes on the head. A miniature circuit breaker is sometimes used to replace a blade – type fuse in the same fuse holder wherever space permits. The APS fuse is called "micro" sometimes since the term means smaller than mini, but recently fuses using the micro name have been released, unofficially.