Maple Leaf Hop Up Chamber for Gas Blowback Pistols (Model: CZ Shadow 2)

"THIS WILL NOT FIT UMAREX 17/18. On the package it reads the list of compatible pistols as G17 GEN 5, G19 GEN 4, G19x, G45. ONLY BUY IF YOU PLAN TO UPGRADE ANY OF THOSE. I bought this for either my Umarex G17 Gen 4 or my G18c and it is too large to fit in either pistol. Otherwise it is of great quality.