With the Duct Donut Spacer you can save time and effort. Your duct bank can be easily pre-assembled outside of the trench. You can also attain either 1" or 3" separation with the same spacer. Up to one third less spacers required on many jobs -- don't over-order Do more work outside the ditch instead of down inside Just slide them on and you have proper duct spacing in every direction -- and from sides and bottom of trench Place them anywhere along the run -- they don't have to be stacked -- this eliminates danger of shear plane in meeting seismic specifications Easy flow of concrete thru spacers in the pour Fits all types of conduit. Sizes for conduits 2, 3, 4, 5, 6 inches Snap out feature allows conversion from 3" separation to 1 1/2" separation.