GREENFIELD — Carl Heebner has for about eight years enticed Circle K customers to donate to the Special Olympics in July by offering to cut or shave his hair. This time around, five of his coworkers have stepped forward to help with the cause.

The Circle K corporation is closely associated with the Special Olympics, and stores in Massachusetts are using donation jars near their cash registers to collect money for the world’s largest sports organization for children and adults with intellectual disabilities until the end of the month. Heebner, a customer service representative for the past 10 years, is promising to shave his beard if customers contribute $1,500 at the store at 223 Mohawk Trail.

“This year, a bunch of other people decided to get in on it,” he said on Tuesday.

Gerry Ahearn has pledged to dye her hair lavender if customers donate $1,000, while Lio Wiles will dye her hair for $2,000, Chris Robertson will dye his for $2,500, and $3,000 will get Kristie Lueders to shave her head. Assistant Manager Becky Burleigh-Howes has vowed to dye her hair red if $5,000 is collected.

Circle K has for years collected donations for the Special Olympics, and Heebner eventually started publicly offering to cut his long hair for $1,000 and shave his head completely for $2,000.

“A couple years ago, we did hit the $2,000 — hence the shaved head,” he said.

Heebner said customers have grown fond of the tradition and ask how much it will cost to generate the most embarrassing scenario. He mentioned he was inspired by memories of Red Sox great Johnny Damon shaving his famous beard for charity in 2004. Last year, Heebner pledged to get a tattoo, but his customers at Circle K failed to meet the $10,000 threshold.

Store Manager Dave Seredejko said customers have so far been very generous.

“We are happy that right now, out of our [New England] district of … [roughly 90] stores, we’re in the lead,” Seredejko said. “It’s changing every day.”

According to Seredejko, $386.65 had been raised by the end of the day Tuesday.

Reach Domenic Poli at: dpoli@recorder.com or 413-930-4120.