Benno Boost models 2019 and earlier (EVO 1, 2 and 3) are compatible with the Benno High Rail* (55cm x 68cm x 20cm), paired with the Rail Clamp Set. To install the clamps and the High Rail, read these instructions. (It's recommended to have a mechanic at an authorized Benno dealer install these parts.)
For the Benno Boost 2020 and later (EVO 4 and 5), you will need the Benno High Rail PLUS* (55cm x 72cm x 20cm) and the Rail Clamp Set PLUS. To install the rail clamps, view these instructions, then to install the High Rail PLUS, check out this installation manual. (It's recommended to have a mechanic at an authorized Benno dealer install these parts.)
*WARNING: When carrying passengers on the High Rail or High Rail PLUS, the rear wheel must be covered. Only use High Rail or High Rail PLUS with Benno Wheel Guards or Utility Pannier Bags. Make sure that no parts of the body or clothing come near moving parts on the bicycle, such as the chain, spokes, tires or brakes. Benno Rails may help stabilize load during normal operation but do not protect in the event of an accident or bike falling over.