Excerpt: using with Canon 6D. the two cartredges provide prolonged shooting time with one canon battery that came with the camera and then rechargable AA batteries ( I use the 15 minute rechargables). this gives me extended shooting hours. it is well made and provides a very sturdy hold in vertical orientation. B&H were very good at substituting this for the free accessories and I paid the difference (that's why I always like to buy B&H).