517eb1a1_Toppers___BedBathandBeyond_com__What_it_s_for
[Mattress Topper Type] Convoluted Mattress Pads [What it's for] 
Also referred to as egg crates, these dimpled foam pads are designed to improve body weight distribution. They add support, help reduce tossing and turning, and add a layer of cushioning to the bed.
Buying Guide to Mattress Pads & Toppers - BedBathandBeyond.com
What it's for