RJ, this version has an Aluminum Rail. The Gen 1 does not have an Aluminum Rail. I have no doubt that the other person could likely have received an older Gen 1 (it depends on when it was made) - (did they say when they received it, serial number?). Buds Customer Service will literally need to verify with their Customer Service Inventory Dept. to confirm this batch as Gen 2 at 1-859-368-0371 9am-9pm EST Mon-Fri. or use the Blue Chat now button at the bottom right corner 9am to 9pm Mon - Sat and 9am to 7pm Sunday.

The GEN 2 comes equipped with a new stabilizer, making it capable of being fired in the folded and locked position. The GEN 1 does not come standard with the new stabilizer, however it IS compatible with the new stabilizer that is featured on the GEN 2, but must be purchased separately. Where as with the GEN 2 it is a standard feature included when you purchase it.
The GEN 2 also comes standard with an aluminum top picatinny rail and the GEN 1 does not.

Hi,
As I said in the previous post, this is Gen 1 model based on the brace it got. However, Buds often use an old stock picture from the manufacturer which are not updated to reflect new products, so I am unsure. That being said, I search on google using the UPC # which shows that the same products being sold by other retailers and all of them show picture of Gen 1 brace. Here's Gen 1 pic (https://caagearup.com/product/mck21-micro-conversion-kit-glock-20-21/) and here's Gen 2 (https://caagearup.com/product/new-mck-20-21-gen2-preorder-free-flashlight/). i am pretty sure it is Gen 1. I hope this helps.