The Speedlite 270EX II features a selectable wide/tele head position and provides a guide number of 72.2' at ISO 100 at the wide position or 88.6' at ISO at the tele position. A 90° tilting head design aids in greater control over the direction of the flash output and, when used in conjunction with EOS DSLRs with a master function, a built-in slave function allows the flash to be triggered wirelessly. It supports Canon's E-TTL II system for fast and accurate flash metering and can cover EF lenses with focal lengths as wide as 28mm with the wide position.