Our Slip Fit Arms are constructed of square or round steel tubing (11G) with 2-3/8″ OD horizontal tenons. Each adaptor is secured with 3/8â€ stainless steel Allen Sets Screws and use black plastic snap-in end caps. They are easy to install by slipping over any existing pole or tenon. Slip Fit Arms feature a very low EPA and are available up to 24″ in length. Consult with factory for a custom configurations.