Model Compatibility: Fits drum cleaning replacement for models 3050ci, 3550ci, 4550ci, 5550ci, 3051ci, 3551ci, 4551ci, 5551ci, 3500i, 4500i, and 5500i only. Quantity Included: Contains 2 pieces of drum cleaning replacement parts per package. Functional Purpose: Designed to restore drum cleaning functionality for the listed model numbers. Specification Match: Matches the dimensional and operational specifications required by the 3050ci through 5500i series drum cleaning systems. Installation Scope: Intended solely as a direct-fit replacement part for the drum cleaning component in the specified models.