This is a extremely lightly used Cingular branded Siemens Handset, it has bluetooth, and GPRS capabilities, its Dual Band GSM and will work on Cingular, T-Mobile, and even AT&T now, since AT&T's merger with Cingular. It is a great Phone, holds a great charge, and it even has a nice speaker phone capability. this was my intermittent phone that i had to use till i got my newer v600. I would like atleast 50 to 75 dollars US for it... i paid 100+ for it... thanks and please PM me or send me an e-mail... thanks....
Take a look for the Phone's specs
this should be a link for the phone's info page at Siemens, or you can select the S55 if thats close!