The Base is made of heavy 3/4" MDF with Melamine finish for easy cleaning. There are 12 sealed ball bearing rollers. Load is evenly distributed to 8 vertical rollers for a smoother and quieter ride and the 4 horizontal rollers keep the Wheel on the Base even at galloping speed of most active cats. The horizontal rollers are spring loaded to keep the wheel running true and it would not come off the base unless you want to remove it. The Base is shipped fully assembled.
The Wheel is constructed with laminated hollow structure plastic and the rims are injection molded high grade plastic. The Track is lined with a textured non-slip Vinyl. It can be cleaned easily with alcohol, sanitized wipe, or mild detergent. The Wheel is shipped in six (6) Track Sections. They snap lock into one another to form a complete circle. Joint tapes are provided to close the seams. The assembled Wheel is light (12 lbs.) yet strong. No tools are required to assemble the wheel. Everything needed is in the box, including an easy-to-follow Assembly Instruction with pictures.