Complete system of compression fittings and adapters for all tubing connection needs in a low-volume system. Multi-diameter compression fittings work with a wide range of 1/2" polyethylene tubing sizes (0.630" to 0.669" or 16mm - 17mm outside diameter). 50% less force is required to connect tubing and fittings versus competitive compression fittings. Adapters swivel for easy installation. Just three Easy Fit Fittings and five Easy Fit Adapters are needed to make over 160 combinations of connections, accommodating countless installation and maintenance situations.