This 3D printed Stainless Steel Magwell is desinged for the Sig P320 X Series. It does fit in the IDPA box if you want to use it in ESP division. This magwell requires the matching baseplates or 21 round mag baseplates. Stock P320 17 round mag baseplates will not fit. Note this magwell is compatible with Gray Guns hard duty & Springer Precision base plates!