Description:Set 7 PCS: 3 PCS 45# Steel Hexagonal Connecting Rod + 4 PCS Converter CRV chrome vanadium steel alloy, good quality material, sturdy and durable, suitable for electric drill, pneumatic drill, electric wrench, hand wrench, pneumatic screwdriver, electric screwdriver etc.Long service life:45# Steel Hexagonal Connecting Rod, Converter CRV chrome vanadium steel alloy, chrome plated, exquisite appearance, high hardness, sturdy and durable.Safety:Square with anti-breakage steel ball, allows compact connection and not easy to fall off, safe and low.Reference:Connecting Rod:Material: 45# steel, chrome platedSize & Color:1/4" Hexagonal outside transformed to square head outside (1/4", length 65mm, gold3/8", length 65mm, red1/2", length 72mm, blue)Converter:Material: Chrome vanadium alloy steel CRV, chromeDimension:Square inside transformed to square outside (1/4"->3/8", 3/8"->1/4", 3/8"->1/2", 1/2"->3/8")Package included:1 x 1/4"Square connecting rod1 x 3/8"Square connecting rod1 x 1/2"Square connecting rod1 x 1/4"Square inside transformed to 3/8" square outside converter1 x 3/8" Square inside transformed to 1/4" square converter 1 x 3/8" Square Converter inside turns 1/2" square outside 1 x 1/2" Square Converter inside turns 3/8" square outside