Sigsauer p365 15 round mag. Has x grip baseplate, but also comes with base plate for regular grip as well. Bought it because I thought it was cool, but I like the 12 rounders more. I also have 10 round mags for sale if you check my other posts. These are discontinued now so they can be tough to find. 
This mag probably has less than 100 rounds through it and has never been carried in ccw. 
$40