Unistrut Channel Nuts fit perfectly inside Unistrut Channel sections to create a perfect anchoring point when connected channel and fittings. P3006-P3009 can be used with any channel series. P3010 is used with can channel except P3300, P4000, P4400, P4520 and P4100. P3013 is used with P3300, P 4000, P4400, P4520 and P4100.