This is a 10cm long forward picatinny rail attachment for the Airsoft Mossberg M590 Springer shotgun. I bought this shotgun at Princess Auto but I believe it can be purchased at Canadian Tire or Walmart. Requires no hardware. I recommend printing at 0.2mm layer height and a moderate speed for your printer. Print with a brim as will. Requires no generated supports or hardware. You will need to break off the supports with a small flat head screwdriver. Refer to the pictures. Simply attach it over the small front sight of the barrel and it should clamp in tightly.