The basepad extensions from Brownells are great!
They do give you more room than do the +2 extensions from PG. This is due to a simpler (BETTER) design. They are (I believe) EXACTLY what you show in the photograph.
These are VERY DURABLE. The all-machined-aluminum construction will not break. They will not slide off due to the (1/16" Hex-head) screw in the aluminum that secures the basepad onto the gun. It does not screw into the gun, but does hold the mag from sliding backwards out of the groove provided in the base plate. (Does that make sense?)
The only downside is that they do not hold +3. I put one on a CZ factory 15 round 9mm high-cap, and it allowed the mag to hold 17 and a half. They are plus 2-and-a-half for 9mm. That would hold an entire +2 for 40, but may or may not allow a 9mm to hold +3.
Conclusion: I have replaced my PG extension on my home defense gun with it, and will never use the PGs again, if I have the money for the Brownell's. These are better all around, but Brownell's should be honest enough to say that they do not always ad +3 capacity to the magazine.
Andy Out.