This drill jig is highly recommended for safely and accurately drilling the rib attach holes in the Cub Crafter wing spars by the builder. The drill jig is precision machined aluminum with all dimensions per the print supplied with the builders manual. The drill jig has (2) hardened steel drill bushings – one # 40 drill bushing & (1) # 30 drill bushing. The drill jig has a blue anodized finish, and includes (2) # 40 & (2) # 30 cobalt drill bits + a stick of Boelube dry drilling lubricant.