A lot of this is I really have little time (and yes, liquid capital) for modding so I try to get as much functionality out of each mod as I can. Here is how to jam THREE couplers onto a 4B, but really you could put the trip coup adapter on anything.
Here are materials, labeled for your convenience. You will also need adhesive (I recommend epoxy and goop) and hotglue for the dead space killin’.

Start by encasing you ½†cpvc coupler within two ½†pvc couplers.

Put that bad boy onto the nub end of your 4B and let dry. You could stop here if you just wanted the two but let’s push the envelope.

Put over the first segment a piece of 1 ¼†PVC and secure with strong adhesive, marine epoxy used here. It is GENEROUSLY used on the inside and outside here. You will want these strongly secured as repeated barrel removal and jamming in place can rip the couplers right off.

Kill the dead space and add stability with hotglue.

Goop your 1 ¼†adapter on there.

Put the internals back in place, BTW this will require some very creative shell cutting.

BAM: CPVC!

BAM: PVC for megas or clips.

BAM: large caliber for barrel pods or other silliness.

And yes: I painted it skin color.

I call it The Flesh! My wife said “that’s ghey, just call it Your Penisâ€. I think this means I win

