Trek OTDR Quad Kit - Singlemode and MultimodeMultimode OTDRs require a pulse suppressor (dead zone) box. We also recommend a single mode zone box with Single Mode OTDRs. Description Description Trek OTDR Quad Kit Singlemode (1310 1550nm) & Multimode (850 1300nm) Most OTDR manufacturers tend to implement an inflexible approach by over integrating four wavelengths into a single OTDR unit. This OTDR takes an innovative approach that very few OTDR manufacturers even consider by including separate