


*ONEAL SIERRA II Flat Adult Adventure Helmet
Marsoni
M251S
Get it in 3 business days with 1 day shipping.
Friday, May 29
*ONEAL SIERRA II Flat Adult Adventure HelmetSIZING CHART Whether you ride on the pavement or the dirt or both the Sierra II has the features you need for your next two wheel adventure. Combining a full windscreen and a visor with a drop down tinted shield, the Sierra II helmet will get you anywhere you want to go. FEATURES: Shell is constructed with ABS Weight: 1590g (50g) Moisture wicking, removable washable air channeled comfort liner Vent holes for optimal ventilation Integrated face shield
Quick Dispatch:
Your *ONEAL SIERRA II Flat Adult Adventure Helmet orders ship within 1-2 business days.
Delivery Options:
- Standard: 3-7 business days
- Fast: 2-3 business days
- Express: 1-2 business days
Order Tracking:
You'll receive a tracking link by email once your *ONEAL SIERRA II Flat Adult Adventure Helmet ships.
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Exchange/Return Notes
- We offer a 30-day return/exchange service after receiving.
- Final sale items are not eligible for returns or exchanges.
- To process your return/exchange, please contact us at [email protected]
- Please click here for more details>>> Return & Exchange Policy
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4.3 ★★★★★
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★★★★★ 2
Missing “C’s” on temple
Size: One Size, Color: Cd472 Black Grey Gradient
Material felt cheap and were missing the “C’s” on both sides of the temples.
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Reviewed in the United States on May 26, 2025
★★★★★ 5
Beautiful
Size: 54 mm, Color: Brown/Grey/Brown Gradient
Beautiful. I love them so much. I wear them all of the time.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on May 8, 2026
★★★★★ 5
Cumplió mis expectativas
Size: 54 mm, Color: Brown/Grey/Brown Gradient
Hermosas y de buena calidad
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Reviewed in the United States on December 26, 2025
★★★★★ 2
Missing “C’s” on temple
Size: One Size, Color: Cd472 Black Grey Gradient
Material felt cheap and were missing the “C’s” on both sides of the temples.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on May 26, 2025
★★★★★ 5
Beautiful
Size: 54 mm, Color: Brown/Grey/Brown Gradient
Beautiful. I love them so much. I wear them all of the time.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on May 8, 2026