I link to Wikipedia for simplicity: http://en.wikipedia.org/wiki/Merkava#Merkava_Mark_IV
http://www.armyrecognition.com/israeli_israel_main_batlle_tank_uk/merkava_4_iv_main_battle_tank_israeli_army_israel_pictures_technical_data_sheet_description_identifi.html
http://www.army-guide.com/eng/product4761.html
http://defense-update.com/directory/merkava4.htm