Description: Expansion Design--The split in the ribbed anchors expand on two opposing sides as you tighten the screw, increasing holding power. Serrated on both sides to increasing the metal anchors hanging to 66lbs. PremiumQuality Materials--Made of carbon steel with zinc-plated for strong structure and maximum durability. Free drilling--No need to drill the holes on the wall. Just a (1-2mm) wide stretch on the wall when removing the anchor, it won’t destroy your wall. Prevent any damage for the wall and no hole left after use. Easy to Use--Compared with convention plastic anchor, Self-Drilling Anchors Screws with tapered sharp head design allows installation and removal become easier, saving your energy. Wide Application--Deep thread design provides strong engagement in 1/4", 3/8", 1/2" or 5/8" gypsum board, drywall, light brick wall board, etc. Work great on hanging all kind of item on your home decor, such as picture frame, wall lamp, curtains, clock, plants, etc. Specification: Material:Carbon Steel, Zinc plated Size Chart: Mutil-color: 12*30mm/0.47*1.18inch Silver: 12*40mm/0.47*1.57inch Package Includes: 20 Or 50pcs Self-Drilling Anchors Note: 1. Please allow slightly error due to manual measurement. 2. Due to the difference between different monitors, the picture may not reflect the actual color of the item. 3. Wish you a wonderful on-line shopping!