Crystal HD Mouth Mirror Head - Size #5 Blue, Plastic 12/Pk. Screw On Head, Cone Socket. 40% brighter than rhodium mirrors. More scratch resistant. Reduces eye strain and fatigue. Lens is flush with mirror frame, eliminating the possibility or corrosion build-up. Eliminates galvanic shock. Autoclavable up to 136 degree C /275 degree F. Contains Antimicrobial Protection. **Compatible with CONE SOCKET mirror handles only. Box of 12 mirrors