Trilogy Valve Stem Help
 

So I'm currently wanting to do the spyder pump conversion. I order a Trilogy valve stem as per the advice given in a lot of tutorials. However, I just got it in a couple days ago and I finally had time to disassemble a marker today. I looked at the valve, then looked at the Trilogy valve stem then back at the valve again. I thought to myself the Trilogy valve stem seemed too small. So I stuck it in and sure enough it was too skinny. The point of the Trilogy valve stem is to disable the blowback, right? Surely air would get past here. I took pics to show you guys. I bought the part from here Did I receive the wrong part? Or has the part changed?
The original valve and stem

The Trilogy valve stem and Spyder valve