i believe that kato released the 2013-1 with a knuckle coupler for the tender end as the factory setting; the arnold coupler for the rear is included in the accessory packet.......please be aware of this unusual - for the big 3 n scale japanese steam locomotive manufacturers - configuration.......
these post introduction of head lamp pre core less motor kato designs - 2010, 2011, 2012, 2013, 2013-1, 2014, 2015 - have aged beautifully - real gems......