Gregory Webster appeals the 252-month sentence the district court1 imposed after granting the government’s Federal Rule of Criminal Procedure 35(b) motion to reduce Webster’s sentence for his post-sentencing substantial assistance. In a brief filed under Anders v. California, 386 U.S. 738, 87 S.Ct. 1396, 18 L.Ed.2d 493 (1967), counsel argues that Webster’s sentence is excessive and unreasonable. Counsel’s argument is unavailing. See United States v. Coppedge, 135 F.3d 598, 599 (8th Cir.1998) (per curiam) (challenge to extent of district court’s departure upon government’s Rule 35(b) motion is unreviewable because appeal was not based on any criteria listed in 18 U.S.C. § 3742(a)); cf. United States v. Noe, 411 F.3d 878, 885 (8th Cir.) (extent of downward departure is not reviewable), cert. denied, — U.S. —, 126 S.Ct. 184, 163 L.Ed.2d 205 (2005); United States v. Williams, 324 F.3d 1049, 1050 (8th Cir.2003) (per curiam) (refusal to depart is not reviewable unless defendant makes substantial showing that court’s decision was based on unconstitutional motive).
Having reviewed the record independently under Penson v. Ohio, 488 U.S. 75, 80, 109 S.Ct. 346, 102 L.Ed.2d 300 (1988), we find no nonfrivolous issues. Accordingly, we deny Webster’s motion for appointment of counsel, and we affirm.
. The Honorable Laurie Smith Camp, United States District Judge for the District of Nebraska.