4 PackSure-step stair treads by Westerly. Rubber treads add traction for safe footing in wet conditions. Deep-groove design allows rain and melting snow/ice to drain, keeping the upper surface clear. Black rubber absorbs heat to melt snow/ice quickly. Safe to use de-icing agents on stair treads - sprinkle on before snowfall for improved performance. Made of 100% recycled rubber 9"W x 30"L