Description These premium concrete knurled drop anchors are made from safe materials and are durable enough to last a long time. Good workmanship and easy to install, just use the power drill and insert the bolts into the holes. Hit with a hammer and then screw on the bolts, giving you a great deal of convenience. Features -Color:Silver.-Material:Galvanised Carbon Steel.-Size:4.00X1.10X1.10cm/1.57X0.43X0.43in.-Note:Suitable for 3/8-40 bolts.- These premium concrete knurled drop in anchors are made of safe materials, durable and can be used for long time.- There is sufficient quantity which can fully meet your different needs, very professional and practical.- Good workmanship, high hardness, sturdy and strong, can be fixed very firmly to concrete.- Easy to install, simply use the electric drill hole, and then insert the bolt into the hole. Hit with a hammer, then screw on the bolt.- Commonly used with machine screws, bolts and threaded rod to anchor fixtures to concrete and other materials. Packing list: 50 x concrete knurled anchors