Most did not have the screw assembly holes drilled deeply enough causing some customers to split the bamboo. So comfy yet stylish! before this I kinda hated flip flops. Thats all it took. 5 depending on the brand, shoe style etc. Nothing seemed to work and some would make things worse. I have a pair of the Treblab XR500s, and they sound outstanding. I think some of this is due to the additional cross bar and the roller axle mounts. I just turned it so the crack faced the wall. You cant beat the product quality for the price!