Coreless design, good penetration, clear and loud sound quality, ringing throughout the game, waterproof and rustproof, can be used in the rain. Choose high-quality ABS environmental protection material, with no color fading, and no coating, that can be directly washed, and durable. Can be used for refereeing, training, safety survival, night hiking, camping, recreational activities, physical education classes, and so on. Portable keyhole design prevents loss and is not easy to fall off. Bright and beautiful color, small and exquisite. Measuring 1.57*0.79 inches, this custom basketball/football game plastic whistle. Usage Scenarios: Office supplies, school stationery, corporate promotions, trade show giveaways. We offer logo printing and full packaging customization. Product Highlights: Portable, durable, practical for daily use.