A serious manufacturer I guess... Has posted so many pics of how their steps attach to the chassis unlike others on the same page, they replied that all I need is a 10mm and a 13mm wrench to install them by myself, here is the link:
http://www.ebay.co.uk/itm/CHEVROLET-CAPTIVA-SIDE-STEPS-RUNNING-BOARDS-/200698668675?pt=UK_Car_Exterior_Accessories&hash=item2eba92a683
http://www.ebay.co.uk/itm/CHEVROLET-CAPTIVA-SIDE-STEPS-RUNNING-BOARDS-/200698668675?pt=UK_Car_Exterior_Accessories&hash=item2eba92a683