The Specialized Pro Road Shoe doesn't use the Boa adjustment dial found on the Expert and S-Works shoe, instead it uses three straps to keep the weight low, and has an increased sole stiffness for a lightweight competition level shoe. 

Specialized's description:

Simple & elegant, the Pro combines a sleek buckle closure, full-carbon sole, and proven BodyGeometry technology to make this shoe a comfortable friend for all day endurance rides.

Key Features:

• Lightweight FACT full-carbon sole uses TorsionBox technology, which increases stiffness for improved power transfer: 11.0 stiffness index
• Performance-enhancing BodyGeometry contours in the outsole and High Performance BodyGeometry+ Footbeds
• New low profile SL2 buckle closure system is designed for lightweight, secure ankle control and adjustability
• Minimalist designed Thermobonded upper with adaptive fit is lightweight, durable and brings a superior supple fit
• Replaceable heel lugs with internally recessed bolts for security
• 3-bolt cleat pattern fits Shimano SPD-SL, Look, Time, and Speedplay