The 139-5J is a Compression Mounting Clamp Assembly for semiconductors to 3.50-inch (88.9mm) diameter. The 139-5 series clamp systems provide electrical and industrial equipment manufacturers with complete system solutions for proper installation and heat dissipation for high-power compression pack semiconductor. The high-quality mounting clamp assemblies are the worldwide standard for mounting, compression and clamping press-pack SCR, thyristor, rectifier and other high power disc packaged devices utilized in power distribution equipment, industrial controls, transportation systems and power supply and conversion systems.