Use the CRL Econ-O-Post Hole Form when setting concrete to allow posts to be set later. The Econ-O-Post Hole Form is sealed from the bottom to keep concrete, water, and debris from entering. The Econ-O-Post Hole Form's shape creates a tapered hole with extra space to plumb posts. Helical grooves allow the sleeve to be easily removed after the concrete is set, when you are ready-to-install the posts. The post size of railing or fence up to 2-3/8" (60 mm) outside diameter and pipe up to 2" (51 mm) square post.