I have 6 M&P Arredondo base pad and extended spring kits for sale. They will fit either 9mm or 40. They are in near new condition with less than 200 rounds through each and did not sit with loaded magazines. For more information about them, please visit their site:
http://www.arredondoaccessories.com/category.cfm?cid=1001,2015&PID=gg13l5513ivuxy&GID=
The magazine bodies and followers do not come with the sale. Arredondo kits only. $17 each
All 6 are sold