The Hollow-Set™ Dropin anchor is designed for anchoring in hollow base materials such as hollow concrete block, brick with weep holes and hollow core pre-cast concrete plank. It can also be used in solid base materials. Hollow masonry materials often have a minimum outer wall thickness of 1-1/2". During the drilling process, spalling on the back side of the wall often decreases the wall thickness available for anchoring to 1" or less. The design of the Hollow-Set™ Dropin overcomes this problem.