Set of 4 Bed Sheet Grippers Sheet Adjustable Straps Thickest elastic, no similar product comes close Higher quality/longer life than shock cord (bungee) type cross corner products Keeps bottom sheets on all mattresses, even hospital beds, hide-a-beds, adjustable beds, inclining beds, baby's cribs and odd shaped mattresses such as those found in boats and RV's Fit any size or type mattress, Filled waterbeds, Baby's Crib sheets 4 - pack;Size : 22cm