SC517, White, Grade 2, Multiswitch Tamper CQR CQR Security has for over 30 years been dedicated to designing, developing, producing and supplying quality service products. These all meet with the latest requirements set out by the EN50131 standards to grades 1, 2 and 3. CQR Website CQR WH-Detection Product Data Leaflet.pdfDetailsDescriptionSC517 G2 Small 4 terminal contact with microswitch tamper. FeaturesThese are suitable for use in Ungraded, Grade 1 and Grade 2 systems. These contacts are required to have a mechanical tamper and/or be potted/sealed. End of Line (EOL) resistors are an option but are not a requirement to meet Grade 2.