Celebrate National Flip Flop Day with a free smoothie from Tropical Smoothie.

Customers wearing flip flops who stop by the smoothie spot today will receive a free 16-ounce Sunshine smoothie from 2 to 7 p.m. The Sunshine smoothie includes banana, orange juice, mango and pineapple.

The annual event serves as a fundraiser for Camp Sunshine, a year-round retreat for children with life-threatening illnesses and their families. The program, located in Maine, is free of charge and includes recreational activities, on-site medical and psycho social support.

Since 2007, the fundraiser has raised more than $5.3 million for the camp.

Find a participating Tropical Smoothie Cafe by clicking here.