Product Features of ER6100 Dictionary: High speed search of over 240,000 words, phrases and definitions covering current and historical English as well as countless specialist and technical subjects. Thesaurus: With high speed search of over 4 million synonym links you will never be lost for words again. Over 365,000 alternative words and opposite words to make what you write and say more interesting. Spellchecker: Instant phonetic spelling correction for over 130,000 words ensures you will always have the answer at your finger tips! Other Features: Crossword Solver - Anagram Solver - Word Games - Calculator & Converters - Self Demonstration Feature - Auto Power Off - Durable Hard Case with integral protective Lid - High Contract Display with wide view angle. Batteries: CR 2032 x 2