Greylock 4

Rated 5.00 out of 5 based on 3 customer ratings
(3 customer reviews)



Product Description

The Greylock 4 torso length under quilt is a 4 season version of the Greylock 3. The Greylock 4 is designed with current state-of-the-art features and is intended for the hammock user who is seeking an ultralight approach to bottom insulation. It is a dual differentially designed quilt and has body contouring radial baffles. In use the Greylock under quilt is effortless to attach and it will maintain its loft under any conditions. The Greylock 4 under quilt comes equipped with full length, channeled shock cord suspension that allows the user to make minor adjustments to their under quilt position. For those desiring to use the traditional JRB corner under quilt suspension the Greylock also comes equipped with corner mounting tabs. When filled with 800 fill power down this torso length under quilt weighs just 22.5 ounces. It comes complete with a JRB compression sack.

Note: Torso length under quilt users typically use their sit pad or back pack as foot and lower leg insulation.

Tip for best results:

Activ-dri down™ – Activ-dri™ is a hydrophobic down treatment that keeps the down drier, while having no adverse effects on loft, fill power, or warmth retention. Activ-dri down is still down insulation and should be protected from direct exposure to moisture. All types of insulation, whether down or synthetic, will degrade in insulation capability if wetted.

Available Options:


  • Length: 56 inches (1.4 m)
  • Width: 42 inches (1.07 m)
  • Loft: 3.5 Inches (10 cm)
  • Material: 0.9 oz., 20 denier, ripstop nylon
  • Insulation: 800 fill power goose down
  • Weight: 22 ounces (0.62 kg)
  • Temperature Rating: 5°-10° F (-18° C)
Special Needs?: See our Available Options


3 reviews for Greylock 4

  1. Rated 5 out of 5

    DCBerry (verified owner)

    Absolutely the best out there was down to minus 38F with windchill and no problems under me! I really like the attention to detail as well!!! Thank you very much!!! BTW I bought mine just over a year ago and figured I could now do a proper review.

  2. Rated 5 out of 5

    Trevor (verified owner)

    Perfect quality, easy to set up and very warm. Doesn’t take up much space in the pack.
    Easy to vent in case you get too warm.
    I highly recommend JRB.

  3. Rated 5 out of 5


    Great quilt. This is now my main “deep winter” UQ, I’ve used it down into the single digits without worry. Thanks for a great product

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