This New U.S. Patented X Bridging System for floors and flat roofs will improve the distribution of loads throughout the entire floor. The ONE-PIECE SYSTEM is connected by a rivet that assembles the two pieces of single bridging through a sliding slot system that SELF-ALIGNS and SELF-ADJUSTS to variances of on center dimensions. They are installed by 4 #6x 1 1/4"coarse threaded screws for excellent hold down power. EZ-X will install faster, look cleaner and help your floor to be stronger with less flexing and squeaking and saving you labor costs. Another advantage of EZ-X the piece can be installed to existing floor joists. Just turn them over & screw them in. VIEW VIDEO They are available in 16" & 12" on center. Proudly MADE IN THE USA.