Caitlin is a streamlined engine from the Mainland.
- Take-n-Play version (uni-polar magnets, 18 wheels) (2013-2014)
- Take-n-Play version (bi-polar magnets, 10 wheels, shorter length) (2015-2016)
- Collectible Railway version (hook and loop couplings, skirting board on tender) (2015-present - Europe/Asia)
- Adventures version (uncovered skirting board on tender) (2017-present - US/UK)
- Caitlin has a front coupler, whilst her front coupler is concealed in the TV series.
- Caitlin's 2013 packaging contains a special King of the Railway design.