Synthetic Half Liner

Lightweight layer inside your bag for additional warmth without bulk

Remedy those super cold nights with the Big Agnes Synthetic Half Liner. Quilted construction with 100% post-consumer recycled FireLine™ ECO Synthetic Insulation, this liner adds between 5-10 F° degrees of warmth to your bag. Attach the liner to loops that already exist in your current Big Agnes bag and can be used as a top or bottom layer.
$29.97 $49.95
100% Guarantee


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Specs + Sizing

Bag Weight10oz / 283g
Fill Weight5oz / 142g
Compressed Bag Size3.5" x 6" / 9 x 15cm
Stuff Sack Size4" x 10.5" / 10 x 27cm
Sleeping Bag TypeComforters, Quilts, Liners


An extra layer for your warm-weather bag on chilly spring overnight, or to wrap up in while watching a free summer concert in the park

Fits any size of bag - petite, regular or long

Attaches to existing loops in Big Agnes sleeping bags as an extra layer of insulation above or below you 

Adds 5-10°F degrees to your bag

Construction + Materials

Nylon rip-stop shell fabric with a water-repellent finish

FireLine™ ECO Synthetic Insulation - 100% post-consumer recycled polyester. Features low-denier fibers that are tightly woven and provide high loft, compressibility, high weight-to-warmth ratio, and durability 

Quilted construction

Length: 68" / 173cm

Here’s what other people think.

What’s in a Name?

This liner is named after the Greek God of warmth - Sin Thetica. Due to it only being one-half of a full bag liner, we decided to commemorate our love of a warm sleeping bag and named this the Synthetic Half-Liner. We may or may not have had a few beers while naming this must-have accessory for cold-weather campers.