Nitecore NWS10 120 dB Titantium Loudest Survival Emergency Whistle with Bonus Lumentac Keychain Light Loudest emergency whistle on the market. You can effortlessly produce 120 decibel sound. Made of titanium alloy - durable yet lightweight Portable and ultra lightweight - only 0.17oz Keychain size - 2.05 inch  0.28 inch  0.28 inch Include a bright bonus Lumentac keychain light