Queen Converter Rail System, Hook-On with Two Center Supports Consists of 2 crossarms with one adjustable glide equipped leg on each cross arm Adjustable glides adjust to a floor to boxspring height of 7 1/4" to 12 1/4" Distance between the Retainer Brackets is adjustable from 54 1/16" to 60 7/8" Converts Full sized headboard/footboard to fit Queen sized mattresses Limited Lifetime Warranty