How to Choose a Bike Helmet

Built around the ball-and-socket design of Spherical Technology, the Giro Merit Spherical Mips bike helmet provides amazing ventilation, deep coverage and luxurious comfort when you're pedaling hard.
Imported.
| Best Use | Mountain Biking |
|---|---|
| Helmet Style | Mountain Bike |
| Helmet Construction | In-mold |
| Shell Material | Polycarbonate |
| Head Circumference | S: 20.1-21.7 inches M: 21.7-23.2 inches L: 23.2-24.8 inches |
| Vents | 15 |
| Visor/Brim | Yes |
| Weight | 12.7 ounces |
| Gender | Unisex |
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It doesnt look like the Portaro Grey variant should be sold any longer due to expiry and recall; it must be on sale due to its age. I loved the color, fit, and look of the helmet I received (Oct 2025). However I noticed the sticker inside indicated a date of manufacture of 2021; if you believe in the 5yr replacement rule for helmets, there isn’t much safe-life remaining. When shopping for another, I noticed the Merit model built before 2023 was recalled due to straps disengaging during impact. Best to go with the non-sale current variants or a different model.