The very first headpiece I purchased for TKD wsa exactly the same has Joshuamonjin's helm, it had a thick plastic face mask, and open from the top, so there was no protection at the top of the head. Straps where in the back, and mines was white colored. For white belts who wanted to spar it was mandatory to have a face mask, it was for insurance reasons.
For Olympic sparring I didn't like using it because a face mask was not mandatory in tournaments and there were no punches a loud to the face. ButI must admit that face mask has prevented me at least on 4 occasions from getting a broken nose. As the months went on and finally years there was no need for it. But when I started focusing on self defense with my brother, once again we went back to the face mask helm. Its a great way to add a bit more realism to your training. Some schools use motorcycle helmets as face masks. I guess this depends how hard you want to hit. You should be creative with your training and try all sorts of training tools to enhance your workouts.
11 years later since I bought it, I now use my face mask helm to practice the straight blast from jeet kune do.
"Poor is the pupil who
does not surpass his
master" - Leonardo Da