PX4 Magazine Extension Kits

Once installed it does not fit perfectly.

I was left wondering why beretta did not included a new metal insert. Otherwise one has to cut the tabs and file them to make this set up work. So buy a pair of wire cutters and a long metal file to install this extension and also get ready to de left with sore fingers. I would pay another $10 for a “complete” set of proper mag extension.

Fit perfect, added 3 rounds to my 15 round msgs, will be taking them to the range to test them out this weekend.

Overall very nice product. Honestly, I do not need extra capacity, simply use to extend the grip on my PX4 Compact Carry. Downside though, there is no installation instructions. There is this weird lock thingy on the extension and took some time/effort to figure it out.

This is the Beretta factory plus three base found on the 20 round full size magazine. It will increase the capacity of your Px4 Compact or Compact Carry to 18 rounds and it will also increase the overall length of your magazine.
The great thing about this kit is it comes with a base plate ready to go in conjunction with the +3 base pad.
I gave it four stars instead of five because the assembly of the spring, base plate, and base pad was somewhat awkward. After assembly, I found that I could load 17 rounds, but the 18th just wouldn't go. The cause was the base plate hanging up on the back of the +3 extension. I found a rough spot and smoothed it out, reassembled only to have the exact same problem as before.
After trying several different approaches with no success, I discovered that if I inserted the back of the base plate into the +3 base pad it snapped into place.
I found it somewhat awkward trying to manipulate the spring and baseplate into the proper position; however, once I got everything properly aligned it all snapped perfectly into place. I had a sample size of one, so your experience may be different.
Once everything was properly assembled the magazine works just fine giving me the option of 18+1 in lieu of 15+1.