A half-cylinder member, about 5 in (12.7 cm) long, coupled to the lower end of a Hall- Rowe deflection wedge, by means of which the deflection wedge may be oriented in a specific manner in reference to a matching half-cylinder surface on the upper end of the wedge (drive wedge). This is driven into the wooden plug placed about 8 ft (2.4 m) below the point in a borehole where a deflection is to be made.