This looks a bit home made, like it was glued together from parts. The spring release system for inserting the SD card often doesn't work first time. The casing is thicker than standard CF cards but fits in my DSLRs (Canon 5D3, 5D2 and 7D) and my card reader. It works with all my 45mb/sec and 90mb/sec Sandisk SD cards but the file transfer speed is slowed. Not a problem for ordinary shooting but it could impair burst mode shooting (I haven't tested this). My main concern is the build quality. One day it might damage a card or (worse still) my camera. CF card slot repairs on DSLRs are very expensive. I think I will stick with SD cards for the 5D3 and CF cards for the 5D2 and 7D. I plan to use this adaptor as a backup only as I have way more SD card capacity than CF cards.