The HERO Disc SUPERSONIC 215 - PROTO GLO features a unique Proto Glo material that enhances visibility in low light conditions, remaining luminous longer than traditional options. Weighing 124 grams with a margin of +/- 6 grams, this disc is designed for consistent performance during day or night play, making each session enjoyable for both dogs and their owners. The varying stamp colors and glow intensity provide a personalized touch, ensuring no two discs are alike.