1. Strengthen anchor wings can provide maximum load carrying capacity, which is practical. 2. Integral threaded adhesive washers can be used for increased reliability, which is with high performance. 3. Combination head on screw has the ability to receive slot and cross-slot screwdriver. 4. Entitled with pratical adoptability, its high quality can keep its high performance for a long time. 5. Built to strict quality control standards, design is improved for more durability.