The Stand Steady FlexPro Hero Corner Standing Desk Converter is designed for L-desks and corner desks. It assembles in two steps and has a keyboard tray.
standing desk converters
The Stand Steady X-Elite Premier Standing Desk Converter comes fully assembled and has a large work surface, but it doesn't have a keyboard tray.
The Stand Steady FlexPro Hero Standing Desk Converter starts at $219.99, has two work surfaces, and has a pneumatic height adjustment system.