I have seen two different stock +2 polymer base plates: the older P-07/P-09 one and a newer, slightly larger and thicker P-10C variant. I don?t know if the P-10C style has a different SKU or is even available for sale yet - the ones I have came on mags I bought.
BTW, I second Earl?s suggestion - the +4 CZ Custom aluminum base pads are super nice. I have the P-07 variant on my carry and training guns and mags and love them.