AS COOL AS IT GETS. GAF Timberline® HDZ™ RS Shingles have rich, vivid color blends never before seen in a cool roof. The enhanced shadow effect and rich color blends of Timberline® HDZ™ RS Shingles combine to give your roof a striking look unmatched by any other brand. With Timberline® HDZ™ RS Shingles, you get proven performance and reliability - plus potential cooling cost savings.