Metric units are units based on the metre, gram or second and decimal (power of ten) multiples or sub-multiples of these. The most widely used examples are the units of the International System of Units (SI). By extension they include units of electromagnetism from the CGS and SI units systems, and other units for which use of SI prefixes has become the norm. Other unit systems using metric units include: * International System of Electrical and Magnetic Units * Metre–tonne–second (MTS) system of units * MKS system of units (metre, kilogram, second)