A new Micro-4/3 mount Speed Booster adapter designed exclusively for the Panasonic GH4 and other selected Micro Four Thirds cameras (refer to the below camera compatibility table), with a magnification of 0.64x. The Speed Booster XL 0.64x uses an advanced 6-element optical design to achieve extraordinary optical performance at apertures up to an incredible f/0.80, a new record for Micro Four Thirds format.