GUILDLINE INSTRUMENTS 9336 & 9337 SERIES of Resistance Standards are designed as very high stability calibration laboratory standards for accurate resistance calibration in air, between 10 MΩ and 10 PΩ. These new resistors complement the 9334A Resistance Standards available from 1 Ω to 100 GΩ. Custom values are available for special applications. These resistors are also suitable for use as calibration standards for the Guildline Series of Teraohmmeters including the following models: latest Series of 6530 TeraOhm Bridge-Meters, 6520 and 6500(A) Digital Teraohmmeters, and 9520 Teraohmmeter. They are also an excellent choice for the calibration of other high to ultra high ohms measuring instruments and standards including Electrometers, Long Scale DMMs, Pico and Micro Ammeters, Meggers, Dielectric Testers and much more.