High wattage, constant-temperature dry block heaters are economical, versatile and compact. These multi-purpose units are ideal for incubation and activation of cultures, enzyme reactions, immunoassays, melting/boiling points and a wide variety of other laboratory procedures. Each of the five models accept separate interchangeable modular blocks, accommodating various sample Enclosures such as micro-tubes, centrifuge tubes, vials, Micro plates, and PCR strips or tubes. Each block has a thermometer well for measuring block temperature. Anodized aluminum modular blocks provide superior temperature stability and heat transfer. Heaters require Ohaus modular heating blocks for operation. Modular blocks are sold separately.