Feature 1FITMENT: 4 red holes for Sprinter 2007 to 2018; 4 yellow holes for Sprinter and Metris 2019 to 2020; 6 purple holes for Sprinter 2002 to 2006; 4 green holes for Transit 150 250 350 2014 to 2023; 6 blue holes for Promaster 2014 to 2020. 2SWIVEL SEAT BASE: With 4 steering clamp slots, this seat base can upgrade your fixed seat to a swivel seat, enabling passengers to effortlessly adjust their seating position for easier entry and exit or enhanced interaction with fellow travelers. 3HEAVY DUTY DESIGN: This 360 degree chair seat base is engineered with a robust swivel plate made from carbon steel and hot rolled steel, delivering outstanding strength and durability. 4RUSTPROOF: The seat rotating base is coated with a protective black paint that effectively resists wear and tear, ensuring a long lasting base that stands up to the rigors of time. 5SIMPLE OPERATING: The heavy duty seat base allows for seamless rotation from 0 to 360 degrees in both forward and backward directions, making it user friendly for all.Item Type: Seat Swivel BaseMaterial: Carbon steel + cold rolled steelSize: Approx. 460 x 460mm / 18.11 x 18.11inRotation Angle: 0-360 degreesRotation Direction: Forward or reverseApplication: Suitable for seat base modification, allowing fixed seats to be converted into swivel seats for easy adjustment of seat orientation, convenient for getting on and off and communicating with other passengers (only suitable for passenger side)Fitment: 4 red holes for Sprinter 2007-20184 yellow holes for Sprinter and Metris 2019-2020 6 purple holes for Sprinter 2002-20064 green holes for Transit 150 250 350 2014-2023 6 blue holes for Promaster 2014-2020 And also apply for T5 T6 Package List1 x RV Seat Base8 x Screws8 x NutsNoteThe installation of the rotating base is quite challenging, we highly recommend seeking assistance from professional engineers to ensure better shopping experience; please pay attention to safety during the installation process.