This is what Seismic says on their website:
Next-level skate bearing tech – more speed, better handling, longer life!
Ultra-Precise Alignment • 50% Stronger XT (Extra-Tough) Steel Casings • Tighter Assembly Tolerances • Dust-Resistant Ball Retainers • Premium Lube
– Superior speed & acceleration
– More consistent wheel contact & grip while cornering
– More predictable slide release & hookup
– Longer wheel & bearing life
PATENTED Spacing System: Built-in half-spacers end in extra-wide contact surfaces (U.S. Pat. #9,126,101) that square up and self-stabilize inside wheels – correcting for flaws in bearing seat levelness, bearing seat spacing, axle diameter, and axle straightness. Combines with Tighter Radial Tolerances (3µ – 5µ) that minimize torsional play inside bearing assemblies. Locks in super-precise alignment, protects against friction and wear – better than any other system. Minimizes noise, too.
XT Construction: More than 50% tougher! Superior steel, thicker outer casings, and advanced heat treatment. Ball raceways hold smooth polish, and bearings stay tight and fast, for far longer! 50%-stiffer casings resist flexing, spin truer / faster, keep seals from popping off on extreme impacts.
7-Ball Assembly: Classic configuration. Best overall durability against frequent high impacts and side loads.
Premium Black Ceramic Balls: (genuine N4Si3 / trisilicon tetranitride) Lighter, smoother, harder, heat-resistant, rustproof. Reduce friction, increase acceleration and speed, scour / clean raceways! A whole new realm of fast.
Advanced Dust-Resistant Ball Retainers: Keep bearings cleaner for longer, without the added friction of a second seal. Formed of Dupont® engineering-grade Nylon.
High-End Lubricant: Packed with premium “high-RPM” light grease from Kyodo Japan. Formulated for peak performance under actual skating stresses, not max free-spin time.
Inner Race: Specially contoured under seal to resist contamination. Extends 0.5mm outside to form built-in washer. No bearing spacers, axle washers, or World Record budgets required!
Additional Features: Black outer casings, removable rubber-coated steel seals with printed graphic. Meets or exceeds all criteria for ABEC-9 rating.
Eco-friendly packaging: No oversized metal tins or plastic boxes – just a minimal recyclable cardboard box.
No fake tech or exaggerations: Just more speed and longevity through real science and no-BS engineering!
100% free of:
• Random bearing tech adapted from other industries just for the sake of novelty.
• Expensive over-hyped raceway coatings that interfere with optimal polishing and may actually grind on balls.
• Over-hyped lubricant additives that accelerate wear not speed.
• Misleading claims that industry-standard features and factory processes are unique or special. (e.g., deep-groove raceways with micro-channels, fine-polishing, fiber-reinforced nylon retainers, hand-inspection, ultrasonic solvent washing, etc.)