I ordered the trial package. The first pair I tried to put in (for slip ons) were ruined just trying to get the sticky thing to adhere to the top inside of the shoe. The flats pair went in easier because they don’t have that section. But I couldn’t wear my flats because the Gekks took up too much space. Haven’t tried the ones for tennis shoes. I gave the product a 1 star rating, just like a lot of folks on this website. My issues were obviously poor design and also high price for something that couldn’t be returned. If you look at the Gekks website you only see 4 & 5 star ratings - something is fishy there.