How does an automatic AV switch work?

Will either the Av switch from Sega Genesis systems 2 and 3 work on the first Sega Genesis system?

• The reason why i am asking this for is because i do have the first Sega Genesis system and i do need to buy an rf switch that does connect from the system to back of the tv and but i do have the av cable one but i rather have the other one just in case if i do need to switch it to a older tv that i do have that does not have no video input lines like the newers sets do have

• Answer:

  I don't think that it will since they do look the same as the first Sega Genesis rf unit though but if you do need a rf unit buy a universal rf unit