In common with benchtop multimeter products, multimeter kits are designed for a wide variety of test and measurement functions. Along with the multimeter itself, which can be either analogue or digital, a multimeter kit will often include a carrying case as well as test leads and probes of all kinds. Supplied in a single package, this allows field engineers to take measurements of resistance, voltage and temperature with a high degree of accuracy, by plugging in the correct accessory when it is needed. Some kits are designed primarily for electrical testing, prioritising current, resistance and capacitance measurements. Others are more focussed on environmental measurements, such as light levels and noise. However, most kits can do a good job of measuring all of the usual phenomena and have the relevant clamps, leads and clips to work in a variety of settings. Unlike power test instruments, such as wattmeters and ergometers, which tend to only provide a single function, multimeters offer multi-purpose use by simply switching modes, usually done through a rotary dial on the front of the device. Digital multimeter kits usually have graphical and numerical displays on the front, whereas analogue versions tend to have a single pointer, which indicates the measurement taken by moving from left to right over a scale.