Bought 2 of these. Actually added +4 to mine so 20+1 in an already awesome little package. Easy install and have worked flawlessly so far. 2 big thumbs up for these guys!
Got three for my stars and stripes version TX22..work great! Fyi- I found that just keeping thumb over base plate when removing and adding new one was best action to not loose spring etc then i removed the mag loading round insert thing after loading up mag it will push right thru round hole! Thanks man!
Purchased 2. They add 4 rounds after your spring gets worked a little. The machining seems off, as I have to make sure the extension is pulled back, otherwise the mag will not fully seat. Has happened several times over the course of about 800+/- rounds. Not particularly happy with it @ $15 a piece. But the +4 rounds do make it nicer (I had to purchase the 10rd mag's in CO).
literally just ordered 2, 3 mins before making this comment. tx22 comes in 2 days from now going to run these mag extensions with a tandemcross gamechanger pro comp, should be fun setup