[01]
Infinergy® Midsole
Expanded ETPU midsole engineered to return over 55% of energy with every step, enhancing cushioning, responsiveness, and long-lasting comfort while reducing fatigue.
AVAILABLE IN 50+ COUNTRIES
ENGINEERED IN ITALY
20+ YEARS PROTECTING WORKERS WORLDWIDE
TRUSTED BY MILLIONS OF PROFESSIONALS GLOBALLY
FIELD-TESTED. WORKER APPROVED
U-Power-ecom
Thunder MF
$136.00
BLACK/BLACK
Size Chart
Measurements in centimeters and inches reflect foot length from heel to toe. U-Power boots feature our Universal Fit, offering a roomier toe box for natural movement and secure heel support for stability.
Already have a pair that fits well? Use our True Fit tool to find your U-Power size.
Use true fit
| US Men | US Women | EU | CM | IN |
|---|---|---|---|---|
| 3.5 | 5 | 35 | 22.1 | 8.70 |
| 4.5 | 6 | 36 | 22.8 | 8.98 |
| 5 | 6.5 | 37 | 23.5 | 9.25 |
| 5.5 | 7 | 37.5 | 24.2 | 9.53 |
| 6 | 7.5 | 38 | 24.8 | 9.76 |
| 6.5 | 8 | 39 | 25.2 | 9.92 |
| 7 | 8.5 | 39.5 | 25.5 | 10.04 |
| 7.5 | 9 | 40 | 25.8 | 10.16 |
| 8 | 9.5 | 40.5 | 26.2 | 10.31 |
| 8.5 | 10 | 41 | 26.8 | 10.55 |
| 9 | 10.5 | 42 | 27.1 | 10.67 |
| 9.5 | 11 | 42.5 | 27.5 | 10.83 |
| 10 | 11.5 | 43 | 28.1 | 11.06 |
| 10.5 | 12 | 44 | 28.5 | 11.22 |
| 11 | 12.5 | 44.5 | 28.8 | 11.34 |
| 11.5 | 13 | 45 | 29.5 | 11.61 |
| 12 | 13.5 | 46 | 30.2 | 11.89 |
| 13 | 14.5 | 47 | 30.8 | 12.13 |
| 14 | 15.5 | 48 | 31.5 | 12.40 |
Select a size to continue
Free shipping · 14-day on-the-job guarantee · 30-day returns
Safety Features
Static Dissipative
SD35
Non-metal Toe
I/C
Slip Resistant, Oily & Wet
SRO
Metal Free Shoes
METAL FREE
ASTM F2413-24 I/C SD 35 SRO
Tech Specs
Materials
Description
Engineered for high-activity work conditions, this athletic safety shoe features a breathable fabric with microfiber reinforcement to help keep feet cool and dry throughout long shifts.
Its 100% metal-free construction provides lightweight flexibility and is ideal for metal-sensitive workplaces.
The direct-injected sole powered by Infinergy technology returns up to 55% energy with every step, delivering responsive cushioning that reduces fatigue and keeps you energized all day.
Article
0UL10324
Shipping & Returns
Shipping
Free standard shipping is included on all orders. Most orders are processed within 1–2 business days and delivered via tracked shipping.
Returns
We're happy to offer a 14-Day Try-On-the-Job Guarantee, allowing you to try your footwear on the job with confidence. We also accept returns of unworn items in resalable condition, with original packaging, within 30 days of shipment.
Policy Details
Please visit our Shipping Policy and Refund & Return Policy pages for complete terms and additional information.
AVAILABLE IN 50+ COUNTRIES
ENGINEERED IN ITALY
20+ YEARS PROTECTING WORKERS WORLDWIDE
TRUSTED BY MILLIONS OF PROFESSIONALS GLOBALLY
FIELD-TESTED. WORKER APPROVED
Thunder MF
–
[INNOVATION]
Down to the detail
[02]
Lining System
Breathable lining system that promotes airflow and efficient moisture management, helping keep feet dry and comfortable throughout extended use.
[03]
Sole Construction
Direct-injection construction uses a dual-density PU compound to bond the sole directly to the upper, delivering enhanced durability, flexibility and reliable grip and slip resistance on wet and oily surfaces.
[04]
Upper Construction
Engineered upper combining premium leathers and technical textiles, built to look refined while delivering the durability and protection required for demanding work conditions.
AVAILABLE IN 50+ COUNTRIES
ENGINEERED IN ITALY
20+ YEARS PROTECTING WORKERS WORLDWIDE
TRUSTED BY MILLIONS OF PROFESSIONALS GLOBALLY
FIELD-TESTED. WORKER APPROVED
Frequently asked questions
Don't see the answer you are looking for?
SEE ALL FAQSWe only use Advanced Performance Materials engineered for workers on their feet all day — not just short-term comfort.
U-Power offers three main safety toe options: Aluminum Toe, Composite Toe, and Fiberglass Toe– for lightweight, metal-free protection. All options meet required safety standards while offering different benefits in weight, comfort, and work environment suitability.
After heavy use:
• Remove dirt with a soft brush or damp cloth.
• Clean the outsole tread to prevent buildup.
• For leather models, use mild soap and water.
• For microfiber/textile, wipe gently — avoid aggressive scrubbing.
If shoes get wet:
• Remove insoles.
• Let them air dry naturally at room temperature.
• Stuff with newspaper to absorb moisture.
U-Power Universal Fit is a design philosophy that shapes the shoe to comfortably fit a wide range of foot types without feeling too narrow or too bulky. Instead of a tight, restrictive safety boot or an overly wide fit, Universal Fit is engineered to provide Balanced toe room and (without excessive bulk) Secure heel hold. Universal Fit means the shoe is designed to feel comfortable for most workers right out of the box — combining safety, stability, and all-day wearability.
U-Power boots should feel comfortable immediately — not painful break-in periods.
We are happy to offer free online returns for orders within 30 days of purchase for products in their original, unused condition for a full refund.
Our 14-Day Try-On-the-Job Guarantee lets you try your U-Power footwear in your actual work environment. If you're not completely satisfied, you can return your footwear within 14 days of purchase, subject to our return policy terms and conditions. We want you to feel confident that your U-Power footwear is the right fit for your job.
Don't see the answer you are looking for?
SEE ALL FAQSOther models with same safety features
AVAILABLE IN 50+ COUNTRIES
ENGINEERED IN ITALY
20+ YEARS PROTECTING WORKERS WORLDWIDE
TRUSTED BY MILLIONS OF PROFESSIONALS GLOBALLY
FIELD-TESTED. WORKER APPROVED
[NEW COLLECTION]
Introducing the Red Fit Collection
Engineered with a three-insole width system to adapt support and cushioning to different foot shapes.