Selling my 550EX flash because I need the funds. Works fine. The battery cover comes off for use with an external battery pack, but locks in place for use with batteries. Comes with white dome Stofen-type diffusor as well (not pictured). Cheaper alternative to the 580EX, can be used as a master flash.
Might be interested in selling the 430EX as well, but I need the 550EX gone first. IF you want both, make offers. Located in NYC. Email at nismode (at) gmail (dot) com for quickest response.