Here's what other sites are saying:
Inexpensive, easy to use visual signal great for kayakers, canoesists, small boat sailors and most other boaters. Heavy-duty vinyl construction that measures 3 square feet. Comes complete with 4-12" nylon ties for easy display. Packed in a resealable storage bag. USCG approved.
"Get the attention of rescuers with the bright orange Orion Emergency signal flag. 2.5 sq. ft. flag features ""HELP"" printed in large black letters; heavy-duty vinyl construction withstands use in the outdoors. Includes four 24 in. tie downs so you can attach the flag to a tree; flag can also be effective when laid on the ground or waved overhead."
Orion Signal Mirror
Orion Alert/Locate Daytime Signal Kit Signal Mirror/Flag / Whistle/Horn / Emergency Light
ACR Hot Shot Signal Mirror
$13 - $18
Coghlan's Sight-Grid Signal Mirror
Coghlan's Survival Signal Mirror
Coghlan's Stainless Steel Mirror
SOL Rescue Flash Signal Mirror
$7 - $9
Coghlan's Featherweight Mirror
$2 - $3