Colonial Mills Boston Common - Winter Blues Stair Tread (single) by Colonial Mills. $19.00. Wool-blend. Durable. Reversible. 65 Polyester/35Wool. A festive blend of traditional and trend-setting colors puts a vibrant stamp on any decor. Reversible for twice the wear. Made in the USA. Dimensions:8 x 28 x 0.5 inches Some assembly may be required. Please see product details.