Amazon.com: BOX USA 10 Pack of Artwork/Mirror Corrugated Cardboard Boxes, 37 5/16" L x 4 1/16" W x 31" H, Kraft, Shipping, Packing and Moving : Industrial & Scientific
UBoxes 3 Picture & Mirror Moving Boxes for Large Pictures up to 40x60" - Walmart.com
4-Piece Mirror Carton (Fits up to 40"x60") Qty 1 | Bring Me Boxes