Savant is a blend of Atom’s Boom and Juke urethane on an oversized core with a molded lip. The oversized core not only reduces weight but increases the overall roll (speed). With the increased speed the molded lip plays a big role in ensuring the grip characteristics remain! Oversized 45mm core 5mm tire with 7mm lip 68 grams per wheel (Over 20% weight reduction compared to Boom Solid Core 59x38) Hardness: 88a, 91a, 93a, 95a, 97a Surfaces: Plastic, Wood, Slick Sport Court UPC 688961068729 ASIN B07CND5PBV Size 8 Pack Pattern Solid Brand Name ATOM Unit Count 1.0 Ounce Wheel Size 45 Millimeters Wheel Type Roller Derby Wheel Item Weight 1.19 Pounds Closure Type Lace-Up Manufacturer Atom Wheels Special Size 8 Pack Material Type Polyurethane Sole Material Polyurethane Wheel Material Polyurethane Manufacturer Part Number unknown