$50-PLAIN DROP AWAY, DOES NOT HAVE LOCK DOWN FEATURE, $100 VERSION DOES. THE HD MODEL IS THE SAME AS THE LD MODEL WITH AN DAMPENER BUILT IN. I HAVE TWO HD MODELS, LOVE THEM...GREAT CUSTOMER SERVICE...IF IT FAILS THEY WILL SEND YOU ONE THE SAME DAY, AS LONG AS YOU MAIL YOUR OLD ONE BACK. THEY HAVE A GOOD VIDEO ON THERE SITE OF IT IN ACTION. I PERSONALLY HAVEN'T USED A BETTER REST....DID I MENTION A LIFETIME WARRANTY.