Even before the first firework lit the sky above Onset on Saturday, July 6, cousins who summer in Onset were raising money for next year’s display.

Rita Gwinn of West Roxbury and Stephanie Saber of Dover realized that sometimes, especially this year when the children got out of school so late, making a donation to the fireworks display is something that falls off the radar.

Before you know it, the event is here.

“We thought, ‘Gee, sometimes I remember to send a check, and sometimes I don’t,’” Gwinn recalled.

So the two came up with a different way to donate. They designed light blue, rubber bracelets labeled “Onset” and ordered 500 of them.

Gwinn and Saber are selling the bracelets for $5 each, with the entire $5 benefiting the Onset-Wareham fireworks.

“It just came out of a matter of thinking we should do more,” Gwinn said.

The bracelets are sold Cup 2 on Cranberry Highway and in seven locations in Onset Village: the Firehouse Cafe, Happy Zone, Onset’s Finest Hair Salon, Onset Village Hardware, Onset Village Market, Stash’s, and the Quahog Republic.

Gwinn stressed that all of the money made will be donated to next year’s event, which will occur during a very special summer for Wareham.

The summer of 2014 marks the 275th anniversary of the incorporation of the town and the 200th anniversary of the British attack on Wareham by the HMS Nimrod warship. Volunteers are already planning a host of events. Wareham is also helping Bourne celebrate the 100th anniversary of the opening of the Cape Cod Canal.