Timberline HDZ shingles are powered by new and innovative LayerLock™ technology. Combined with all the benefits of America’s top-selling shingle, LayerLock technology mechanically fuses the common bond in Timberline HDZ shingles to offer: – Up to 99.9% nailing accuracy thanks to our new StrikeZone nailing area – up to 600% larger v. Timberline HD shingles – Up to 30% faster nail fastening during installation v. Timberline HD shingles – Dual-phase shingle-to-shingle seal with our Dura Grip sealant and StrikeZone nailing area, and an asphalt-to-asphalt monolithic bond for durability, strength and powerful wind uplift performance – Compatibility with Timberline HD roofing shingles