This is an ORIGINAL front barrel band for the UBERTI 1866 and 1873 carbine Made by UBERTI , reproduction . They will fit on the 1866 and 1873 Winchester rifles, they just don't have the integral front sight on the top. The screw for this band is part number wp631. This band should sit in front of the front sight with the head of the screw on the left side.
NOTE: These are often not available, but you can use the Uberti part ub21 in most cases.