Does not work with winchester sxp - Choate Tool Winchester SXP SX Pump Magazine Extension

Some good parts. It was easy to order online. It arrived promptly the same week.
Not so good. The instructions are poor, but YouTube comes very handy.
More good parts. It fits nicely and in the end the process of installing it is nothing difficult.

Now the terrible part. Despite Winchester SXP in the name of the product, it does not and can not work with Winchester SXP if your shotgun is anything like mine. The reason is that inside gun's magazine tube there are two little bumps that keep original spring retainer in place. Well, these bumps would not let a round through. So the round cannot exit the original magazine tube to enter the extension tube. And with the extension installed the capacity of your magazine stays as it was before. And this is a shame. It is also a strong indication that the maker of the product never tried the product with Winchester SXP. Otherwise they would know. After all, I'm just an amateur and it took me less then 30 minutes to figure it out.
Disappointment.