I received my PM50 on 9 September. It worked well, and accurately, but after ten days I noticed the SPO2 recorder was cutting off after three hours (10240 seconds), even though the SPO2 measurement and display on the screen continued. The manual said both the BP and the the SPO2 recording time should be 48 hours. The BP recording time was normal. Only the SPO2 data was not saved completely. On 20 September I explained my problem to Contec and after several weeks (delayed by the Chinese holiday season) of testing by me and sending files back for analysis by their engineers, they understood the problem, solved it, and sent me a software upgrade (from Ver 2.4.1 to VER 2.4.1) that made my PM50 work as expected. Everything was done in English. Their customer service is very good.
good, quality,