Eight new seat shocks covering E30, E23, E24 and E28 seats + custom tool for installation!! The toughest part of this job is figuring out how to compress the 400N gas springs during install as its a much greater force than human hands can generate; we have solved this by making a custom tool. These new gas spring shocks cross reference to the following OE numbers: 52101965645 52101916601 52101965632 52101965646 These 8 shocks are 400N each and work perfectly for both the seat back and seat base.   The ends of the tool are 3D printed from PETG and have sleeve bearings.   $250 for the full kit + $10 shipping to North America (US/Canada)   $250 for the full kit + $20 shipping globally outside of NA   $80 tool only +$10 global shipping (NA inclusive)