No contact, no noise, internal working method, no spark noise generation. Good optocoupler operation for more stable power cycle capability and excellent temperature characteristics. The shell is made of transparent high-temperature flame-retardant material, which is glossy, heat-, fire-, and dustproof, sturdy and . Solid state relays do not have mechanical components and are operated by thyristors to complete contact work. Electroplated aluminum plate has excellent heat dissipation., Weight: 0.25683853523 Pounds, Manufacturer: Kueohse