Wilson Anchor Sleeves are used with one diameter of anchor bolt and all sizes are colored black. Contec Anchor Bolt Sleeves are used with at least two different diameters of anchor bolts and in some cases three. Each size of Contec anchor sleeve is easily identifiable by different colors for each size. Contec Anchor Bolt Sleeves often must be cut on each end in order to be used with the diameter of anchor bolt being set into concrete. Other than color difference and the fact that Contec sleeves can be used with multiple diameters of bolts, there are virtually no differences between the two sleeve brands. See this FAQ for more information.