Heart-2-Heart Handcuffs Double Locking Black. Give up control, relax and go with the flow you are their prisoner of love once they have you in these dramatic black handcuffs from Heart 2 Heart. The double locking mechanism protects your wrists by not allowing the cuffs to close any further after it has been set. They lost the key? Do not despair these come with a spare! Also available in nickel.