These mag blockers are design to reduce the capacity of your stock P365 X Macro magazines to 15 rounds. They are machined from aluminum and hollowed out to be lightweight if that's what you want OR you can add Tungsten weights into the cavities to make back the weight lost from the missing rounds. Adding weights reduces felt recoil and makes the mags drop faster and more reliably from the gun. (Weight kits sold separately).
These mag blockers are easily, and permanently, attached to the magazine springs with the included one way screws, and maintain the ability to strip down the magazine for easy cleaning. So you don't lose out on that functionality from poorly epoxied or riveted magazines but maintain "compliance".
Made in the USA to be very robust these will put up with abuse and come with a Lifetime factory warranty against defects in design or manufacturing (does not cover cosmetic issues from use or dropping mags).