The model as pictured it can fit various sized bases, please message us if you have a specific requirement - most options in this set will fit as small as a 105x70mm/100mm base - but there will be a bit of overhang from the tail.
Mounted characters are 28mm scale,
dinosaur is designed for 28mm or 32mm tabletop games.
Models come in around 5-10 pieces and come with 2 heads for you to choose from. You will need to assemble the set with glue suitable for resin.
This is a prebuilt kit from the 'Build Your Own Dragon' listing, 
Merchant license obtained from: https://www.myminifactory.com/campaigns/where-is-my-dragon-1010
Models are made to order.