Unlocked but not jail broken

[Kinskeys]

I just got a used iPhone 4 today it's unlocked but not jail broken, how can I jail break it without losing the unlock? It's on 4.3.5 & 04.10.01 thanks in advance

[Mes]

Tethered jailbreak is the only thing available. Be aware, it's still beta.
The details (4.3.5 + iOS5): Dev-Team Blog - redsn0w iOS5beta

...how can I jail break it without losing the unlock? It's on 4.3.5 & 04.10.01...

If your phone is factory unlocked, that never goes away.

[Kinskeys]

Yes but redsn0w could make my phone unlockable right? I'm on the H20 and can't lose the unlock

[i.Annie]

Jailbreaking cant make factory unlocks go away. Like Mes said if it is factory unlocked it will never be lost.

[Kinskeys]

Jailbreaking cant make factory unlocks go away. Like Mes said if it is factory unlocked it will never be lost.

But I don't know if it's factory unlocked & can't risk losing the unlock

[Mes]

Search your model number, factory unlocked models are identifiable. The search will not include carrier locked models which can be unlocked by the carrier. However, both are unlocked forever.

[i.Annie]

If it is not jailbroken, it cannot be unlocked, unless you pop open the SIM tray and see if there is a turbo SIM in with the SIM card. If there is no turbo SIM in the SIM slot and it is not jailbroken, it is likely a factory unlocked if you are not using the official carrier that the phone belongs to.

I agree with Mes though, search the model number. Or call Apple and give them the necessary info and they can likely tell you if it is a factory unlocked device or not.