SPAX® T-STAR Washer Head PowerLags® with HCR® coating designed with low-profile, large diameter head design provides outstanding clamping force and improved aesthetics. The T-STAR drive offers excellent bit engagement without requiring a special driver bit. Available in 1/4”, 5/16”, and 3/8” diameters. SPAX HCR® Coating is approved for use in treated lumber.