Crimp couplings must be installed by a fully trained assembler with appropriate machinery. Always confirm crimp ODs & tolerances. 4S Fittings are used on EC525 (in sizes -12 to -32 Only), GH493 (in sizes -6 to -32 Only), FC736 (in sizes -6 to -32 Only), FC254 (in sizes -12 to -32 Only), FC500 (sizes -12 to -24), EC415 (sizes -6 to -32), EC600 (in size -12 to -16 Only) & EC810 (in sizes -12 to -16 Only). *These are used for ease of installation only, they are not designed for constant swiveling or movement. They are also not recommended for high temperature or pulsating hydraulic systems at all due to the internal O-ring.