General description maXpeedingrods B1 series coilovers are designed for Vauxhall Astra G Mk4 (1998-2004) and provide an excellent solution for replacing old struts while enhancing handling performance. These adjustable suspension lowering kits maintain the original equipment (OE) ride quality while allowing for height adjustments. Technical specifications Front Lowering: 30-75mm (depends on vehicle models) Rear Lowering: 25-65mm (depends on vehicle models) Damping: Fixed Damping Spring rate Front: 8 kg/mm (448 lbs/in) Spring rate Rear: 3 kg/mm (168 lbs/in) Front spring inner diameter: 62 mm Rear spring inner diameter: 49-60.5 mm Spring length Front: 170 mm Spring length Rear: 210 mm Helper spring rate Front: 1 kg/mm (56 lbs/in) Helper spring length Front: 102 mm Spring Preload advised: 7-10 mm Type: T98MONOCAB Compatibility and accessories Compatible with: Vauxhall Astra G MK4 (1998-2004), Vauxhall Zafira A (1999-2006), Opel Astra G (1998-2004) Not compatible with: OPC, GSI, and 2.0