From the website:
Preorder Man-O-War Assault/Siege Chariot by May 7, 2018, and receive a FREE Black Anchor Heavy Industries Trucker Hat.
This kit includes:
Horses (x 2)
Weapons and equipment for Man-O-War Assault Chariot
Weapons and equipment for Man-O-War Siege Chariot
Preorders ship at the end of May 2018. Quantity limited to the first 1,000 preorders. The Man-O-War Assault/Siege Chariot will be available as a normal item in the online store after June 1st.