2nd Skull® Cap
- Impact Absorbing Technology
- Ultra-Lightweight
- Multi-Sport
Info
For over a decade, the 2nd Skull® Cap has protected athletes of all ages across helmeted sports.
A patented protective skull cap engineered with XRD® Extreme Impact Protection, the 2nd Skull® Cap fits comfortably under any sports helmet, adding a layer that helps absorb impact forces. XRD® Extreme Impact Protection is flexible at rest and instantly hardens under sudden pressure to help mitigate impact. A spandex fabric blend delivers a stretchable, compressive fit — lightweight and durable.
Trusted by youth, high school, college, and professional athletes, it's built for football, hockey, baseball, softball, lacrosse, ski, BMX, and more. Year-round protection, in games and practice — football in the fall, hockey in the winter, baseball in the spring.
Technology featured on The Science Channel and Sports Illustrated Studios.
The 2nd Skull® Cap moves with you — one layer of protection that never comes off your gear list, no matter what you're playing next.
Features
- Impact Absorbing Technology: Soft protective skull cap that helps absorb impact forces
- Comfortable: Thin 2mm design fits under sports helmets
- Great-looking protection: Designed after accessories pros already wear
- Ultra-Lightweight: Weighs less than 3 oz.
- Moisture-wicking fabric to keep you dry
- Anti-microbial treatment for anti-odor
- Permitted by NFHS for high school use
- Fabric: 80% Polyester, 20% Spandex
- Hand wash only
- Made in the USA
Size Chart
| 2nd Skull Cap | Inches | Centimeters |
|---|---|---|
| Youth | 19” - 21” | 48.3 - 53.3 cm |
| Teen/Adult | 21” - 24.5” | 53.3 - 62.2 cm |
| X-Large | 24.5” - 26” | 62.2 - 66.0 cm |
Conversion: 1 inch = 2.54 cm, rounded to 0.1 cm.
Find Your Perfect Fit
Measure your head circumference 1 inch above your eyebrows using a soft tape measure. If you're between sizes, choose the larger size.
| 2nd Skull Cap | Inches | Centimeters |
|---|---|---|
| Youth | 19” - 21” | 48.3 - 53.3 cm |
| Teen/Adult | 21” - 24.5” | 53.3 - 62.2 cm |
| X-Large | 24.5” - 26” | 62.2 - 66.0 cm |
Conversion: 1 inch = 2.54 cm, rounded to 0.1 cm.
2nd Skull Cap vs Over the Helmet Cap
2nd Skull Cap vs. Over the helmet protection
Over the helmet caps are heavy, limited to one sport and practice.
| Feature |  |
Over the Helmet Caps |
|---|---|---|
| Multi-Sport | ||
| In Game | ||
| Lightweight | ||
| Helmet | ||
| Made in USA | ||
| Price Range | $65.00 | $74.99 - $89.99 |
Year Round Protection.
See how athletes use 2nd Skull to stay protected across ports without losing their competitive edge. Real protection, real results.
2nd Skull® Cap
A thin, lightweight protective skull cap designed to fit comfortably under sports helmets.
Impact Absorbing Technology
XRD® Extreme Impact Protection, absorbs energy when impacted
Helmet-Ready Fit
A thin, lightweight 2mm protective layer designed to fit comfortably under most sports helmets.
Ultra-Lightweight Comfort
At only 2.3 ounces, it let's you play at your fastest version.
LIHGTWEIGHT PROTECTION
Low-Profile Defense, Game-Ready Comfort
The 2nd Skull® Cap adds a thin layer of Impact Absorbing Technology, featuring XRD® Extreme Impact Protection. Its lightweight, moisture-wicking design stays cool and comfortable without adding unnecessary bulk.
Built for Sports Helmets
Designed to fit comfortably under most helmets, adding extra protection without changing your feel or fit.
Play without Distractions
Moisture-wicking fabric helps manage sweat while the lightweight fit stays comfortable through every play.
Multi-Sport
Stay protected throughout the year. For football, baseball, hockey, lacrosse, softball and more.
FAQ
Got quick questions? Here is everything you need to know about 2nd Skull protection, fit, and care.
How does 2nd Skull® Technology work?
2nd Skull® uses an independent floating protective layer nested between two fabric layers. Because this protective layer floats independently rather than being fixed in place, it allows slippage on impact—which is what lets it guard against both rotational impacts (angled or twisting forces) and linear impacts (direct, straight-on hits).
The protective layer itself is made of XRD® Extreme Impact Protection material. The advanced material is soft and flexible during normal use, but upon impact, it instantly hardens to absorb and dissipate the energy from the impact. It then returns to a soft state.
Will it fit comfortably under my helmet?
Yes. Both the 2nd Skull® Cap and 2nd Skull® Pro Cap are designed to be worn under sports helmets without having to upsize. They fit seamlessly under any standard helmet (football, hockey, baseball, lacrosse and more) without changing your helmet size.
Can I use it for multiple sports?
Absolutely. It is a multi-sport protective gear. And works under sports helmets such as football, hockey, baseball, softball, lacrosse, and more.
How do I wash and maintain it?
We recommend hand washing it with cold water and a mild detergent, then letting it air dry. Do not put it in the dryer, as high heat can damage the protective XRD® material.