What's the sizing like on these jackets? I'm 5'7ish and aboput 38.5" round the chest. Should I get the small or medium. My current Sessions jacket is a medium, but I think another 686 I had was a small.

Tech Specs:

Material:

[Shell] InfiDRY 100% polyester dobby with DWR finish 

Insulation:

[Liner Jacket] fleece; [Liner Vest] 60g poly fill 

Waterproof Rating:

[Shell] 20K 

Breathable Rating:

[Shell] 15000g 

Core Venting:

[Shell] Underarm zips, chest zips 

Pockets:

[Shell] 2 hand, 1 internal goggle, 1 internal mobile, 1 internal audio, 1 internal storage, 1 internal earphone, 1 pass, 1 card, 1 mirror; [Liner Jacket] 2 hand; [Liner Vest] 2 hand 

Seam Taped:

[Shell] Yes, fully 

Powder Skirt:

Yes, removable 

Hood:

Yes 

Zip-in / Snap-in Compatibility:

Yes, removable liner & vest included 

Recommended Use:

Snowboarding 

Manufacturer Warranty:

2 Years