The Headway photoresist spinner is an intermediate spinner between the Laurel Spinner (Resist Spinning Only - No Wafer Cleaning) and the Solitec Spinner (General use spinning and cleaning) used for spinning on SU8 and photoresist - no SOG please . The Headway Spinner has two chucks. The 4" chuck is designed for spinning and cleaning 4" wafers. The smaller chuck can be used for smaller items such as glass slides and 3" photomasks. Below are guidelines of basic operation and cleaning.