Johnson Level JTS48 Professional Aluminum Drywall T Squares, 48"Extruded aluminum blade and head with clear silver anodized finish. Screened, thermal bonded 1 8" graduations in black, exclusive design. Solid 4 rivet construction permanently bonds head to blade. 48" Unique rivet assembly, permanently "bonds" head to blade Head will stay square for life of product Extruded aluminum 1 8" blade and head thickness Clear protective anodized finish will not rust or corrode Screened, thermal bonded black 1 8" graduations