Valve made identical to the OEM drawing.

Fits following engines: B20E/F,B30E/F
Diameter: 35mm

Primary advantage is the tip hardness which is 50RC as per Volvo specification.
Typical aftermarket valves are made from 21 4N stainless, which can only attain a tip hardness of 25RC unless a stellite wafer tip is added.
Tip is a critical wear point, having the additional hardness is good insurance.