VEVOR Bike Trailer for Toddlers, Kids, 60 lbs Load, Tow Behind Foldable Child Bicycle Trailer with Universal Bicycle Coupler, Canopy Carrier with Strong Carbon Steel Frame for Children, Blue and Gray

Because of the packaging, the tubes on both sides need to be telescopic structures when folding. This ring is for your convenience when opening the product. You can unfold it by simply pulling the tube.