MIKASA whistles

BEATMASTER

High Volume and Clear Sound
Suitable for Volleyball and Other Sports
With Nylon Strap (with Safety Device)
Made of ABS Resin

PULMASTER

High Tone and High Volume
Suitable for Volleyball and Other Sports
Light Weight and Comfort Design for Referees　
With Nylon Strap (with Safety Device)
Body: 5.2g
Made of ABS Resin

http://www.mikasasports.co.jp/e/accessory_top/g5/