TWIN SIZE DOWN MATTRESS-Feather Bed-New/tags-topper/pad Willow Highlands Willow Highlands, 39" x 76" x 4" Standard Twin Size Down Pillow Top Mattress Pad. This mattress pad is also great for rejuvinating an older bed's mattress, or increasing the comfort of a sofa bed. The unique two-layer design provides you with a super-soft comfortable top layer of down, and a firmer, more supportive lower layer of small feathers and down. The 13 oz. top layer of down is composed of a minimum of 85% fluffy down with a minimum fill power of 525. The 11 pound lower layer is composed of 95% small feathers, and 5% fluffy down. Note: Fill power is a measure down's loft per ounce. This mattress, with 525 fill power, is considered high quality for a mattress pad.