HSP has 4 outlets (just like a wall outlet) and 4 probe ports on the back. Each probe is configured to that outlet only, allowing 4 completely different temps per outlet. I have a 7 level rack with 2 continuous strips running. The first one is for the upper 3 levels and the next strip is for the lower 4. The lower levels are my breeding levels so I have a night drop on them and the upper 3 are my juvis.
The other 2 ports are used on my burms tub (one for belly heat the other for ambient heat control.
Also if you have more than one flexwatt strip going to the same port you can try and find a none grounded extension out let to allow for more plugs to go into the one port.
I can have pics of it after I get off work.
I LOVE this unit. I can have 4 different settings on it at once for different animals if needed. Once the ball lay they will get on the same temp so only 1 prob will be needed and the extra probe will be used in the incubator.