Cobra 501R Parawedge Anchor, 1/2"x3-3/4"Highlights: Parabolically curved for a smoother expansion, it also has a torque controlled expansion and can be installed into a bottomless hole It is cold formed to increase its strength and has a 360 degree clip for more contact Size : 1 2" x 3 3 4" Quantity : 4 WARNING: This product can expose you to chemicals including Chromium (hexavalent compounds), which is known to the State of California to cause cancer and birth defects or other reproductive