A great Jacket that I only used for one season. 4X sounds big, but I'm 5'10 and a little plump at 245 and the jacket felt good on me.

Below is what I found listed from a store about this item.

Alpinestars Andes v3 Drystar Jacket

The Andes v3 Adventure Jacket uses Alpinestars' exclusive Drystar waterproofing technology to transport riders comfortably into any variety of on- or off-road conditions. The rugged textile chassis features polymer-printed panels at the elbows and forearms, contrasting multi-density fabrics and a multitude of adjustment straps and vents.

Pockets on the front, rear and interior keep your riding essentials organized and readily at hand. Moving past the jacket's exterior, a full-sleeve thermal insert and impact protectors for the shoulders and elbows are included. The Andes v3 also provides pockets for optional Nucleon chest and back protectors. With these provisions in mind, the jacket achieves a CE Class A certification. For an additional level of protection, the Andes v3 Jacket is also compatible with the Alpinestars Tech-Air 5 airbag system.

Fit:

• Customers have found this jacket runs small and recommend sizing up one size from what size chart recommends.

Construction:

• Advanced abrasion resistant polyfabric textile construction and reinforcement
• Removable long-sleeve thermal liner
• 3D mesh internal lining

Waterproofing:

• Waterproof Drystar breathable membrane

Ventilation:

• Direct ventilation system (DVS) zippered chest air intakes and back exhaust ports

Protection & Safety:

• Removable shoulder and elbow impact protectors included
• Compatible with Nucleon back and chest protector inserts (sold separately)
• CE approved to EN17092 as a Class A garment
• Alpinestars Tech-Air 5 airbag system compatible (sold separately)
• Reinforced polymer-printed texturing in critical elbow and lower arm areas for enhanced abrasion resistance
• Reflective details for improved rider safety

Comfort:

• Integrated soft edge collar
• Pre-contoured sleeves with accordion stretch panels on elbows
• Hook and loop waist adjustment belt
• Shock cord adjustment on hem

Pockets:

• Front waterproof cargo pockets
• Large, external stash pocket on lower back
• Waterproof interior wallet pocket

Other Features:

• Premium YKK zippers
• Jacket-to-pant full connection zipper