I use these blood ketone test strips regularly and they are very accurate. One of my family members has type one diabetes and we need to check for ketones when they are unwell or running high numbers. These need to be accurate as one mistake can be life threatening. Easy to use and read and do not require a lot of blood to test. The box contains 50 strips. They work with a variety of meters including most Freestyle meters that are adapted to read ketones. They are a little more pricey than other brands but they are accurate and that is what you need when using these. Bargains are best saved for other things because it is the accuracy you are paying for here. I trust them.