This COD heater block features digital microprocessor control, programmable timer and temperature settings, and a dual LED display to monitor both temperature and timer. Perfect for COD, Total Phosphorus, and Total Nitrogen testing PLUS other tests requiring digestion.

Help kids understand the life cycle and habitats of freshwater aquatic macroinvertebrates with this set of flashcards and manual. The 22 full-color cards feature photos of both immature and adult insect stages, and detail life cycle and habitat information. The accompanying manual contains facts on insect characteristics, life cycles, taxonomy, classification, food webs and how macroinvertebrates can be indicators of water quality.

Instructions for activities with the cards are included. The Freshwater Aquatic Macroinvertebrate: Insect Life Cycle and Habitat Flashcards can be used as an extension to the Freshwater Aquatic Macroinvertebrate: Identification Flashcards and the Leaf Pack Experiments Stream Ecology Kit.

Use this set of 18 full color flash cards alone or as an addition to any macroinvertebrate activity. (Included in the Leaf Pack Experiments Stream Ecology Kit). The front of each card features a full-color photograph of a common macroinvertebrate in its natural environment. A list of dichotomous characteristics, a measuring scale, and detailed drawings on the back of each card aid in the identification process.

Helpful notes prevent confusion between macroinvertebrates with a similar appearance. A hole can be punched in the wide border of the laminated cards so they can be organized on a ring for field or classroom use.

A precision, NON-MERCURY thermometer, furnished in a protective plastic jacket with a window opening. Engraved graduations on white tubing increase the readability over the full range of -5° to 45°C in 0.5° increments.