Starbrite - Big Boat Bi-Level Brush - Medium - 10" - 40015 Medium duty Bi-Level 10" head for all-around cleaning of soiled and stained surfaces. Starbrite Extend-A-Brush heads are made with Star prene, a lightweight polymer fiber that does not stain, discolor or become brittle. It resists most cleaning chemicals and withstands heat up to 200F. The lightweight synthetic block will not rot, mildew or absorb odors. Features: Medium duty Bi-Level 10" head for those big cleaning jobs. 10" head covers a lot of area for fast cleaning. Excellent all around brush. Fits all Extend-A-Brush Premium Handles.