If you are a conditional resident in the United States, you will receive a U.S. re-entry permit that only lasts as long as your conditional green card period.
Conditional green cards are given to those who seek adjustment of status through K-1 entry. Conditional green card holders have the same rights as LPRs, but the green card is only valid for a period of two years. This is to ensure that the marriage in which you became a permanent resident is bona fide, or in good faith.
To remove conditions, you will need to file Form I-751. Once you have been granted lawful permanent residency, you will have your unrestricted green card and be able to have a re-entry permit that lasts for the full two years.