RTI Inlet filter for R-134a units comes assembled ready to install. Installs on the fitting of the high and low side inlet ports of your recycling unit. Constructed of solid brass for durability and long life. Screen mesh element is replaceable. The mesh is small enough to catch debris, rust and particulates that could possibly harm your recovery unit. Easy to install and maintain. Use one on each side of your unit. To install simply remove existing inlet fitting and replace with this unit.