Mossberg 590 RM or M 10 round mag.

  Mossberg 590 M or RM 12 ga , 10 round mag. Compatible  with both the M and RM, according to Mossberg web site and confirmed it fits a RM. Retails for $192 plus tax, but most are sold out currently.  Will sell for $200 plus shipping, but prefer to trade for 5 rd mag to fit same 12 ga.  
 Appears to have not been used , in box with plastic and instructions.  

Located near Ingersoll, Ontario.  If trading, I’d prefer a somewhat local deal, willing to meet if not too far away.