For 8' or 10' high garage doors. Includes rail extension, replace chain/cable, and all necessary hardware. Use with Do it Best private label or Chamberlain garage door operators. The 8' or 10' chain drive SSR kit works with model No. PD212D (SKU 121347), No. PD610D (SKU 117285), No. PD210D (SKU 121169), No. PD752D (SKU 103144), and No. PD612EV (SKU 100318).