4300-38 - Rx11-flush Liquid AC/R Starter KitNu Calgon 4300 38 Rx11 flush Liquid AC R Starter Kit Rx11 flush Liquid is a new and improved chemistry that is the next generation in flushing technology. It remains a constant boiling solvent and is now stronger, faster acting and dissolves more oil, moisture and contaminants than any other flush. It is ideal for line sets, burnouts and other flushing requirements. Features The industry standard for flushing refrigeration and air conditioning systems