ACR Auto Hemilight 4. Smaller than other approved lights, the HemiLight features rounded edges to maintain the integrity of inflatable life jackets. Attachment loops accommodate up to 5 cm (2 in) wide webbing, and the marine tough design ensures years of useful service.

The high-intensity flashing LED light automatically activates for 20+ hours when it comes in contact with salt or fresh water, and can be deactivated simply by pushing the red button. Installation is quick and easy (the HemiLight can be retrofitted to almost any style life jacket in a matter of seconds).

Available in two configurations: the HemiLight offers a basic strobe mode which can be activated either manually or automatically.