There is an excellent review of a very similar unit, the Contec CMS 50E from Arizona Willie that can be found here:
viewtopic/t28525/Report-on-CMS50E-Pulse-Oximeter.html
I bought the CMS 50F which is similar in many respects.
The picture here shows the unit and gives a lot of information:
http://www.semedicalsupply.com/cms-50f.htm
There is a larger one here that shows the display:
http://img.diytrade.com/cdimg/499627/62 ... imeter.jpg

The number to the left is the oxygen level, the number on the right is the pulse rate. Down below you can see your pulse as a wave form.
This unit goes on the wrist and has a rubber fingertip attachment. The attachment is fairly comfortable and doesn't come off easily.
The unit has a lithium battery and is capable of recording for 24 hours. The battery recharges using USB or an included charger.
Reporting and software is very nice and the same as the 50E. You get full night summary reports or detailed reports.
Unlike the CMS 50E, it has a clock chip. You don't have to set the clock each time you start recording.
When it is in recording mode the unit "goes to sleep" and turns off the screen. However, it is possible view your pulse and oxygen while you are recording. If you press the button the display comes on and it will stay on for a minute or so before turning off again (the display is off while recording to save the battery).
The unit is well made to all appearances. The menu system wasn't particularly hard to get around in. The manual is in "Chinglish" but as such things go it's really pretty good.
I had a good experience ordering from http://www.semedicalsupply.com. Service from them was very good. I had a small problem (I wasn't doing something right) when downloading the information and they were very helpful and quick to respond.