MII Part Number Part Description 53258 Screened to MIL-PRF-38534, Class K; DC operation, Single channel., Normally open (SPST, 1 Form A); 1000V input to output isolation, Radiation tolerant Select 53274 Screened to MIL-PRF-38534, Class H; DC operation, Single channel., Normally open (SPST, 1 Form A); 1000V input to output isolation Select 53250 Screened to MIL-PRF-38534, Class K; DC operation, Single channel., Normally open (SPST, 1 Form A); 1000V input to output isolation, Radiation tolerant Select Micropac offers a wide portfolio of solid state relays (SSRs) for switching up to 10A in industrial, medical, military and space applications. Some devices include radiation tolerant provisions suited for radiation environments commonly encountered by spacecraft or in medical radiation treatment equipment. Most products are rated for operation from -55°C to +125°C.