Roller kelly bushing is a necessary tool for drilling, by matching with rotary square to drive kelly pipe. Through the rotation of four rolls, the friction between rolls and kelly pipes is reduced to extend service life. Change different rollers to match with different squares and hexagonal kelly pipes and connect with different rotary tables. Two transmission styles (square and pin connect) are available. The product is designed and manufactured according to API Spec 7K Specification for Drill Equipment.