GM-44721-20 Power Steering Adapter is required to adapt to GM-44271, Power Steering Analyzer, previously essential, to properly diagnose the power steering system on the Buick LaCrosse and XTS vehicle with banjo-style fittings, to determine if the power steering pump, power steering gear or the power steering hydraulic lines are working correctly. GM-44721-20 includes male and female adapters to connect the vehicle power steering lines to GM-44721.