This Radial Engineering SW8 MK2 comes with the correct power supply. It's a great choice for audio line - level switching. However, please note that the rack ears are bent and the screws are rusty.

Using the Radial Engineering SW8 MK2 is quite straightforward. First, connect it to the correct power supply that comes with it. Then, you can start using it to switch between different audio line - level sources. When handling the product, be careful with the bent rack ears. Try not to apply too much force on them as it may cause further damage. Regarding the rusty screws, avoid using sharp objects to remove the rust, as it could scratch the product. For maintenance, keep the switcher in a dry and clean place. Regularly check the connections to ensure they are secure. If you notice any abnormal performance, disconnect the power supply immediately and consult a professional.