Silent Runner Cage Attachment includes two brackets used to attach your Silent Runner Wheel directly to your wire cage. One size fits all Silent Runner wheels. Does not fit other wheels designs (i.e. Wodent Wheel). The new & improved Cage Attachment Brackets are a larger size than the previously attachments and now provides greater surface area to create a sturdier mount and better support for the wheel. The attachment is also now made of heavy duty plastic to help absorb extra movement or sound from the wheel while attached to the cage. Allows you to attach your Exotic Nutrition Silent Runner wheel directly to the cageIncludes 2 brackets measuring 7 inches x 4 inches x 1/2 inch.One size fits all Exotic Nutrition Silent Runner wheelsQuick and simple instructions on packaging