I had no idea what speed card to purchase for the Zoom Hn4. My sales advisor said the cards they sell have been tried and work. So I got this card. My only complaint is once it's loaded and the Zoom is turned it takes forever to get started. Patients is not a virtue within me. The card handles everything I've thrown at it with easy. An bonus to me being a photographer is the card also works in my camera after formatting for said camera.