Compatible with FS1028, FS1128, FS1350, FS2000, FS2020, FS3900, FS3920, FS4000, FS4020, KM2810, KM2820.This lower pressure roller bushing spring is a replacement part designed to restore functionality.Part numbers include 302H425121, 2FB20170, 2H425120, 2H425121, 302FB20170, and 302H425120.