Rotary 4" Adapter Extension for SPO12 Lifts (-10, 300, 400 and 500 Series) provides additional lifting height when vehicles require additional clearance and can also be used to level a vehicle on a lift. Note: Do Not Stack Extensions. Local sales tax rates will apply on all Rotary Lift purchases that are drop-shipped from the manufacturer. When purchased with a lift, additional discounts may be available. Please call for better pricing.