These K&N S2000 filters are washable and reusable and are custom designed to fit into the existing Honda S2000 factory air box. Their drop-in design means adding performance is simple.

Part E-2435 Product Specifications
Product Style: Unique Air Filters
Filter Material: Cotton Gauze
Flanges: 1
Height: 7.563 in (192 mm)
Base Outside Diameter: 7 in (178 mm)
Filter Re-Oiling Amount: 1.73 oz (51 ml)
Flange Inside Diameter: 3.75 in (95 mm)
Flange Length: 2.875 in (73 mm)
Flange Type: Centered
Top Material/Finish: None
Top Outside Diameter: 3.75 in (95 mm)
Top Style: Rubber
Weight: 1.9 lb (0.8 kg)

E-2435 Cross Reference
Honda 17220PCX003
Honda 17220PZX003
Napa 2726
Ryco A1457
 

K&N E-2435 fits the following:
2009 HONDA S2000 2.2L L4 F/I - All  
2008 HONDA S2000 2.2L L4 F/I - All  
2007 HONDA S2000 2.2L L4 F/I - All  
2007 HONDA S2000 2.0L L4 F/I - All  
2006 HONDA S2000 2.2L L4 F/I - All  
2006 HONDA S2000 2.0L L4 F/I - All  
2005 HONDA S2000 2.2L L4 F/I - All  
2005 HONDA S2000 2.0L L4 F/I - All  
2004 HONDA S2000 2.2L L4 F/I - All  
2004 HONDA S2000 2.0L L4 F/I - All  
2003 HONDA S2000 2.0L L4 F/I - All  
2002 HONDA S2000 2.0L L4 F/I - All  
2001 HONDA S2000 2.0L L4 F/I - All  
2000 HONDA S2000 2.0L L4 F/I - All  
1999 HONDA S2000 2.0L L4 F/I - All

K&N's premium oil filter HP-1004 was designed to fit the 2004 to 2009 Honda S2000's with the 2.2 liter engine and the 2000 to 2007 Honda S2000 models with the 2.0 liter engine.  The HP-1004 uses thick canister walls for extra strength and durability which helps reduce the risk of damage from loose rocks and debris.  It was designed to allow high oil flow rates while maintaining filtration levels necessary to ensure long engine life.