Envirokleen certified thermometers feature green, non-toxic, biodegradable, enviro-safe liquid against lead-free, white back glass. total immersion pocket thermometers are a compact 160mm 6.3in long come with a case to protect from breakage ideal for field studies, waste water treatment and any inon-the-goin applications case options include: oplastic window – encased in plastic with an open windowometal window – encased in metal with an open windowoclosed plastic – housed in removable plastic caseoclosed metal – housed in a removable metal caseoaluminum duplex – encased in nickel-plated brass with an open window and housed in a removable aluminum case manufactured and tested by our usa quality team traceable to nist include a multi-language english, french, german, italian, portuguese, and spanish statement of accuracy and traceabilityshould you require an individualized thermometer calibration report, custom calibration services are available.