Catalog number: 401-693 Features: ●A scientific whistle that emits a frequency of 3150Hz, which is the easiest for the human ear to hear. ●Compact and lightweight, it resonates powerfully even with a small breath. Specifications: ●Width (mm): 47 ●Depth (mm): 20 ●Height (mm): 8 ●●Compact and lightweight, perfect for carrying around ●Does not float when attached to a strap
