Available in two and four wheel models and is designed to handle heavy CRYOGENIC LIQUID GAS CYLINDERS|This larger sized frame and repositioned front wheels which allow secure handling without excessive force|The 650A50-51 is designed to handle larger 20" -26" diameter liquid gas cylinders|This model equipped with the QUAD Hook will handle a wide variety of large gas cylinders|Newly designed single hook adjusts from 50" to 60" in height which makes it more versatile for handling a variety of cylinder types