A pack of shower door wheels 4x upper wheels and 4x bottom wheels.This button roller features buffer springs for an easy and firm installation process. Its strong and reliable design provides superior durability for long-term use. It is suitable for flat sliding shower doors and curved sliding shower doors.The top roller on this product has no buffer spring, allowing you to precisely adjust the wheel's position with an adjustable screw. Enjoy consistent and accurate positioning of the roller.This roller is made with heavy-duty zinc alloy brackets and stainless steel smooth and wear-resistant nylon wheels, providing superior durability and strength. Its wheels make it an excellent choice for everyday use.