Flexible Flyer Ground Stakes for Amusement Park Gym Sets. Hours of backyard fun for your kids and their friends! Keep the kids safe by staking down your Flexible Flyer Amusement Park Gym Sets with these Ground Stakes. AVAILABLE SEPARATELY: Flexible Flyer Double Coaster Gym Set; Flexible Flyer River Rider II Gym Set; Flexible Flyer Amusement Park Gym Set; Flexible Flyer Madison II Gym Set; Flexible Flyer Windsor II Gym Set; Flexible Flyer Time for Fun Gym Set; Flexible Flyer Cumberland Gym Set - word search in our Store for "Flexible Flyer". 4-Pk. Flexible Flyer Ground Anchors