Angelina are they only for design, or do they have a purpose?
I copy from Tollyboy:
Secondary shield with 2 rows of stainless steel 'needles' which are blunt and do not cause injury to the wearer. This is fitted to the crotch guard on female appliances, designed to prevent oral, vibratory and finger stimulation. Located on either side of the vaginal slot, concealed within the confines of the secondary shield, these 'needles' act as a further deterrent to finger tips and other tactile stimulation. Forming a full vulvo-vaginal cage it proves to be a very effective barrier. Our secondary shield has the additional practical function of protecting the labia from getting squashed when the wearer sits, wears tight clothing, drives etc. This function is enhanced by the 'needles' that guarantee a safe and constant distance between crotch guard and secondary shield without compromising at all its primary function of preventing stimulation. A highly recommended addition to all female appliances.