The HKS Hipermax S is a full coilover kit for the GDB (Applied A-D) Subaru Impreza WRX and STI, built on a large-diameter monotube damper with 30-level adjustable damping and length-adjustable shock bodies so ride height can be set without preloading the spring. HKS's Dual PVS (preload valve system) tames damping force at high piston speeds for street ride comfort, and DURA BOOTS protect the shaft. Front spring rate is 59 N/mm (6 kgf/mm) and rear is 29 N/mm (3 kgf/mm), backed by a 3-year warranty.
| Type | Coilover kit (HKS Hipermax S) |
| Adjustability | Ride height + 30-level damping |
| Damping | 30-way manual, monotube |
| Construction | Large-diameter monotube with Dual PVS and DURA BOOTS |
| Spring Rates | Front 59 N/mm (6 kgf/mm) / Rear 29 N/mm (3 kgf/mm) |
| Contents | Full kit (front and rear coilovers) |
| Warranty | 3-year manufacturer warranty |
