Doncouri Wells directly appeals the 300-month sentence the district court 1 imposed after he pled guilty to a child sex-trafficking offense. His counsel has moved to withdraw, and has filed a brief under Anders v. California, 386 U.S. 738, 87 S.Ct. 1396, 18 L.Ed.2d 493 (1967), arguing that the sentence is substantively unreasonable. Wells has filed a pro se supplemental brief, arguing that a Guidelines enhancement should not have been applied.

In his written plea agreement, Wells stipulated that a sentence of 300 months in prison would be reasonable and appropriate. At his change-of-plea hearing, he confirmed under oath that he had freely and voluntarily entered into the plea agreement, including the stipulation regarding a 300-month prison term, which was below the statutory maximum of life in prison. Thus, upon careful review, we decline to review the issues raised on appeal. See United States v. Olano, 507 U.S. 725, 733, 113 S.Ct. 1770, 123 L.Ed.2d 508 (1993) (waiver is intentional abandonment of known right and results in issue being unreviewable on appeal); United States v. Nguyen, 46 F.3d 781, 783 (8th Cir. 1995) (defendant who explicitly and voluntarily exposes himself to specific sentence may not challenge it on appeal). Having independently reviewed the record pursuant to Penson v. Ohio, 488 U.S. 75, 109 S.Ct. 346, 102 L.Ed.2d 300 (1988), we find no nonfrivolous issues that are appropriate for review. Counsel’s motion to withdraw is granted, and the judgment is affirmed.