Specifications include, but are not limited to: Ehiem thermocontrol e - 200 WThe Eheim thermocontrol e is a top of the line, fully submersible aquarium heater designed for both freshwater and saltwater environments. The heater itself takes on the classic "hang in the water" design, but elevates its functionality with incredibly precise temperature adjustments between 20 C and32 C, accuracy within 0.5 C and dry-running protection to offer unmatched safety and control. The unit has been constructed with a state-of-the-art glass jacket that increases the heating surface and acts like a heat shield, ensuring optimum heat emission and uniform distribution around the tank. For greater ease of use, this ultra modern electronic thermal device requires zero readjustment for accurate results, a convenient 170 cm long plug in cable, a double suction cup holder to securely place the heater anywhere in the tank and a easily visible control lamp that indicates red for "heating up" and green for "temperature reached". The heater has an output of 200 watts and is ideal for aquariums between 79 and 106 gallons in size.; Sedgewick Rafter Counting Cell Slide the Sedgewick Rafter chamber is constructed as a flat slide Skjmm x 40mm x 2mmTIonto which is cemented a RwallRIto form a chamber or cell in the middle. This chamber is 50mm long x 20mm wide and 1mm deep and its base is marked with a grid of 100 x 1mm squares. When filled with liquid and with a cover glass placed over the chamber a 1ml volume of liquid is trapped. When used under a low magnification light microscope, each of the grid squares equates to 1 microliter of liquid.