This is The Referee Forum's "Whistle of Choice" as used in the Everton Celebrity Football match played at Goodison Park on 22nd May 2022.
 
Product Name: Dolphin Whistle
Weight: 6 grams (single whistle)
Volume: about 130 decibels
Size: 6.2*2.8*1.8cm
Material: ABS hard plastic
Gifts: mouth guard*3, lanyard*1, hand strap*1
Application: basketball, football and other ball sports, physical education, training, outdoor activities
Features: pealess, imitating dolphin shape, loud sound, strong penetration
Color: black