I ordered this when my husband was sick and in the hospital...he has COPD and we needed to keep track of his vitals...this works wonderfully and is so easy to take with us when we go out. I would recommend it to anyone who needs to keep track of oxygen levels. Have had it for close to two months and no problems with it working, the visiting nurse liked it also!

I use this daily in my nursing school clinicals. I have compared readings to a higher-caliber pulse-ox unit in a hospital with favorable results.
I spend most of my clinical hours in sub-acute settings with elderly patients, and manage to get fast readings on nearly all of them. I have gotten consistent readings on a patient with severe COPD issues. The only times I've had difficulty obtaining a reading were with a couple of patients who had very cold or very contracted hands. I managed to rub the cold hands to warmth for a reading, and I think I took a reading from the contracted patient's toe.
Other students regularly borrow this device, so it gets a good amount of use. So far it has held up well through all of the usage and alcohol wipes.
I love that this device is really easy to read. I could have saved some money and purchased a cheaper pulse ox, but I'm very happy with its ease of use, reliability, and readability.

I have been using this device for five years. I have treated it roughly, hauled it all over the country in my pocket, my purse, down the neck of my shirt. When compared to professional pulse oximeters, the reading are spot on or very close, so it's accurate. Only maintenance in five years has been to change the batteries about once a year. I don't think there is any way this could be better. (Well, other than if I didn't need to use it, but that's neither here nor there.)

I have been really impressed by this device. I'm a bit of a technophile, and this thing has numbers and a moving graph. It's great. I love the auto on/off function and night visible screen. I've even used it on my sick daughter while she was sleeping once to make sure she was getting good breaths in. It provides some reassurance when you're not sure if you need to wake her up to take her inhaler.

This is a tool I will keep in my home medicine cabinet from now on.

The Santamedical SM-240 works with finger inserted facing toward or away from you, and easily readable with unit in any position. The OLED display glows so it is readable in low light. Pressing the button turns it on, and continued presses change readout orientation - a very useful feature. It fits in this $5 carring case: http://www.amazon.com/gp/product/B001D0OSLS?psc=1&redirect=true&ref_=oh_aui_search_detailpage

I got the device to replace a Nonin Onyx oximeter that I bought about 12 years ago for $400 for use at high altitude. It had begun to read about 5 points low. The Nonin unit has an LED that flashes with pulse - a great indicator that the unit is reading properly - and bright red LED display that face away from the wearer - designed for use by an attendant. It also had auto-on - which might have turned the device on sitting near radios etc: The batteries didn't last very long, and I learned to store them outside the unit. I don't expect to have such a problem with the Santamedical unit.