I don't have one so I am just shooting in the dark. I just made a bubble trap for my Remora Pro and it is basically a box with sponge the water has to go through. So, it (the trap) has to go on the water return, on the Remora it just slips over the return "chute" the water runs down and tightens on with two screws.
I just looked at a picture of the BakPak and it has a tube returning the water - your bubble trap probably screws onto the tybe.
Sorry I can't be more help. You might just e-mail CPR and see what they say.
[ May 11, 2001: Message edited by: CaymanLovers ]