Sig Sauer, the masters of product differentiation with so many models it is hard to keep count, have introduced a new magazine for the P238. The extended length magazine holds one extra round (seven vs. six rounds) and has a pinky finger rest. Strangely, they are not selling them individually but only with certain model P238s.
UPDATE: Photo added:
[ Many thanks to John @ Sig Sauer Blog for emailing me the info. ]