ITEM NAME:1/4" & 5/16" & 3/8" & 1/2" Bearing Diameter Flush Trim Pattern Router Bit Description: High-grade welding, stable quality, high efficiency. Using for kinds of woodworking. Totally enclosed and lubricated . Car.1/4" (6.35mm) & 5/16" (7.96mm) & 3/8" (9.52mm) & 1/2" (12.7mm). Blade length: Approx. 20mm (0.79") & 20mm (0.79") & 20mm (0.79") & 25mm (0.98"). Pls allow 1-2mm error due to hand test. Color: Silver.