The mini RDA unit with fastener is designed for low torque sensors. Engineered to provide consistent and reliable torque readings for use with low torque power tools. The mini run down adapter is mounted in-line between the tool drive and torque sensor. The kit includes 5 mini RDA units along with 10 fasteners. Operates in clockwise direction only.Note: Change screws when thread wear occurs. (Recommended - approximately every 25 run downs). The Mini-RDA unit is not made of Stainless Steel material. The mini RDA unit with fastener is designed for low torque sensors BMX20z - BMX10i and MTX models. Screws:PH Phil 10-32 x 1/4 SS