Forget cluttering your bench with a pile of connectors, bits of wire and crocodile clips to see if you have a decent connection, this box will save you all of that in a multitude of cases!
It covers the really awkward ones like network and telephone cables too - almost impossible without something like this.
One niggle is that the RCA connectors can turn, being round, this potentially breaking the internal wiring, so be careful not to let them work loose like that. It’s a small fault that a bit of consideration can easily get rid of.
This will change your world as a person who fixes things! Buy it.
Extremely solid build too, being made of mild steel.
Lots of testing sockets ended up getting this model, it does not have 3.5mm jack tester but not a problem. I just use a 6.3mm to 3.5mm adapter, bought this one because it has cat5 test socket on it. Its quicker than using a test meter which is a pain on a dark stage, looks tough enough not to be a problem in future.