The SCUD is basically a calibrated tank (in 5 litre graduations), a pump which pumps the chemical out of the envirodrum into the SCUD tank and the micro-matic fittings, which are dry couplings that connect onto the envirodrum and a rinsing socket, that allows the system to be flushed with water after each batch.
The SCUD's main advantage over other systems is that it measures volume not flow, so 5 litres of water is the same as 5 litres of thick chemical. The accuracy of a flow meter will vary with different chemical viscosity, that is why they require different settings for different chemicals, which leaves them open for operator error. Because the SCUD doesn't use a flow meter it eliminates this problem.
The SCUD is always set up, so no matter where you are all you need is the chemical and a water supply. This also saves a lot of time when filling, so you spend more time in the paddock and get more done in the day.
The SCUD is safe. The chemical is transferred from the Envirodrum to the boom tank in a completely closed system, which protects the operator from toxic chemical fumes and chemical splash.