They include a liner so that you can layer the pants for colder weather or shed the liner for those warmer days out on the mountain. They are size Medium and are a straight fit, these are not a slim fitting snowpant. 

Below is the information from 686:

Description

- infiDRY® 20K Recycled Fabric + DWR

- Fully Taped Bemis® Seams

- Removable SMARTY® 3-in-1 Stretch Poly Fleece Pant Midlayer

- UltraDurable Fabrication

- Wrapped Side Seam Design for Added Durability

- Core Ultra Thread

- Hidden Seam Stash Pocket

- Double Duty Waist Snaps

- Air-Flo™ Mesh Lined Inner Leg Vents

- Boot Gusset with Snap Closure

- Pant Jacket Connect™ System

- BOA® Compatible Boot System in Gaiter

- Boot Gaiter and Boot Lace Hook

- External Waist Adjustment

- Tricot Inner Waistband

- 500D Horseshoe Hem™

- 500D Reinforced Inner Kick Panel

- Belt Loop Stash Pocket

- Lift Ticket Eyelet on Belt Loop