Most builders would agree that blocking out a lally column to prep it for sheet-rock or paneling is way too time consuming. Now there is a better way. Use these nifty plastic collars to frame out 4" steel columns quickly and easily. The hinged halves of the collar fit around the column and are simply screwed together in just one place with the included screw. Hinged plastic shim tabs allow one collar to fit 4" columns. Collars should be mounted on 24" centers to provide adequate panel or sheet-rock support - most eight foot ceiling height applications require 4 collars.