This model is extra pace and reliability. Sadly, Blacksn0w unlock for iPhone 3GS is still crippled in this version. If you have iPhone 2G, 3G or iPod touch 1G/2G, you can use sn0wbreeze to jailbreak iPhone OS 3.1.3.
For those of you who don’t know, Sn0wbreeze is a jailbreaking tool like PwnageTool for iPhone and iPod touch which can be used to create custom .ipsw files. But unlike the PwnageTool, Sn0wbreeze is fully compatible to work with Windows machines.
You can also use Dev-Team’s PwnageTool 3.1.5 which can jailbreak iPhone 2G, 3G, 3GS (older bootrom and with baseband 04.26.08) and iPod touch 1G/2G on 3.1.3 firmware.
Once you are done with jailbreak, you can then unlock your iPhone using ultrasn0w.