This whistle not only puts out a surprising amount of high pitched noise, but it also has a small waterproof capsule with a slip of paper for emergency information. It weighs next to nothing, so keep it on your keychain or anywhere else so you can always have a whistle when you need one, and emergency information for the unexpected situations. Whistle is made out of aluminum and is anodized red. The label features a red cross symbol and reads: "WHISTLE ID - In case of emergency open capsule." The emergency information slip was made by non-English speakers, so it might be a good idea to make your own before filling it out.
Please note that the pictured battery is not included and is just for size reference.