This is a newly made front barrel band Winchester 1866 and 1873 carbine Made for the original Winchester not reproduction and comes in the white. This is the type 2 front band carbine made after serial number 49,000. They will fit on the rifles made prior to that, they just don't have the integral front sight on the top. The screw for this band is part number 631. 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.