Got a Sony DSLR? Expand your creativity with the revolutionary HVL-F20AM compact external flash, which extends illumination range beyond the camera's built-in flash. Bounce flash enables shadow-less indirect lighting while TTL (through the lens) flash exposure is automatically controlled by your a DSLR for easy and intuitive operation all in an ultra-compact design which folds flat when not in use. Wireless flash trigger function (DSLR-A900 only) - When teamed with the a900, the HVL-F20AM can also be used to trigger wireless flash setups. Please note, however, that this functionality is only available with DSLR-A900, and does not include luminosity ratio control. ADI (Advanced Distance Integration) flash metering system offers the optimum flash metering and automatic white-balance compensation regardless of the background conditions or the subject's reflectance Includes soft carrying case Uses 2 AAA Batteries Guide Number = 20 Unit Size - 3.75 x 2.5 x 1 (94 x 62 x 24mm) Weighs about 3 ounces