Mastercool 93561 Includes: Standard Hoses with Standard Fittings Packaged in a Clamshell Silicone dampened gauges smooth out needle movement Gauges can be easily recalibrated in the field to maintain accuracy Extra large sight glass for visual refrigerant check Large easy-to-grip knobs 2-Way Aluminum Manifold Gauge Set, R600a, R290, R134a Mastercool is the leading manufacturer of professional quality A/C manifold gauge sets. Our manifold gauge sets are constructed of the finest materials and machined with precision to the highest quality standards. At Mastercool, every manifold we build is built to last.