The ServoCity 3.50" Foam Wheel (2 Pack) features a 16mm hole pattern, designed for compatibility with various applications. These wheels are crafted from foam, offering a lightweight solution with a total weight of 1.44 ounces. They are engineered to be adaptable, allowing for integration with goBILDA® hubs through the use of specific adaptors and hardware, ensuring a secure and stable connection. This product is ideal for projects requiring a balance of durability and lightness, making it suitable for a range of mechanical and robotic applications.