When visualizing the signals from modular synthesizer on the oscilloscope,  there is often a need to redistribute them (either to somewhere else in the patch or to a mixer). Of course this is a problem you can solve with some extra cables and mults. However, when you’re working in a small lab space, the ensuing cable spaghetti tends to make things confusing after a while. For this reason ThreeTom created the ThreeTom Wiretap, a 2-way mult that you can directly mount onto a BNC connector. This way, you can have your connections directly at the oscilloscope, making it much easier to keep track of a test patch.