I put some of the quick fit ones on my MCW6000, luckily I got one off with pliers, and the other I had to take a jigsaw blade to by hand n cut it into about 6 different pieces, but not before it threaded the fvck outta my barb. I bought an MCW50 with 1/2" adapters attached, I plan on using 3/8" tubing, and again I could only get one out, and the other is stuck. Is there some secret method I don't know about or was Swiftech just retarded when they made these things?