Marlow provides TE modules with three different types of ceramics depending on customer and application needs. The three ceramic types are aluminum oxide (alumina or AlO), beryllium oxide (BeO) and aluminum nitride (AlN). These different options for ceramics provide cost/performance advantages. AlO is the most common and lowest cost ceramic and can be provided with direct bond copper (DBC) for larger, higher current TE coolers for medical or industrial applications, or thick-film copper with nickel and gold plating for smaller telecom and defense applications. AlN is a high-performance (high thermal conductivity) substrate that can be provided with copper metallization and nickel and gold plating for telecom applications. BeO is also a high-performance ceramic that is sometimes used in telecom and defense applications that can be provided with thick-film copper with nickel and gold plating.