Once you decide on whether you need an adult or pediatric pulse oximeter then you can go online to purchase the device. You can simply just go to Yahoo search engine and type in oximeter. You will see websites that provide oximeters. It is very important that you pay attention to the fact of whether the devices are FDA approved. Once you see that they say that they are FDA approved then you can start deciding which model to purchase in particular. Say for example that you are actually looking for a oximeter that is for an adult. Well, you will have basically two choices for the oximeter. You can either choose the color screen oximeter or the black and white screen. Although there is no difference in the accuracy of these models there is however a convenience difference as well as a price difference. Those oximeter with color tend to be more expensive than those that are not color. However, those pulse oxmeter devices that do have a color screen provide great convenience when reading the readings of the device. With a color screen you can easily see the readings on the screen of the device in almost any lighting situations. This is a significant convenience improvement over the non-color screens.