The 574 Alert/Locate Plus is the same as the 544 kit, with the addition of a signal mirror, whistle and distress flag.
It also includes the new high performance aerial signals.

12-Gauge safety launcher
(4) 12-Gauge high performance red aerial signals
(4) handheld red signal flares
(2) handheld orange smoke signal
(1) signal mirror
(1) SOLAS and USCG approved whistle
(1) CG approved distress flag
Storage case
Note: This item can be shipped within the US by ground via common carrier (truck), but will incur a $35 (6/24/13) hazmat handling fee if shipped via UPS or FedEx; CANNOT be shipped by air, nor via USPS