E Mechanism     Also known as ‘Split E’.  This is an automatic mechanism (i.e. the player doesn't need to alter fingerings) that holds down the lower G key when fingering third octave E.  It improves the venting for this note and, therefore, makes it easier for most players.  It is usually recommended as standard on beginner flutes but for the more advanced player it is worth noting that a G to A trill in the third octave becomes awkward.  It is also worth noting that an E mechanism can cause problems on an 'In-Line' open holed flute unless it has a 'Pinless' mechanism. On normal offset G flutes (both closed and open hole) there is no mechanical problem associated with E mechanism.