The Canon Speedlite 550EX is a high-performance strobe ideal for professional photography. It works after changing the batteries. - Model Name: 550EX - Brand: Canon - Accessories: Dedicated case Information found: Thank you for viewing. The product shown in the image is the Canon Speedlite "SPEEDLITE 550EX". It is a clip-on type strobe (speedlite) manufactured by Canon. It is compatible with the EOS camera system and supports E-TTL auto flash control. The guide number is 55 (at ISO 100 and a 105mm angle of illumination). It uses four AA batteries for power. It is no longer in production and is only available on the used market.