You will find two mesh :

- 1 water gallon - real world size (18.9 L) - Tap is parented - 

- 1 small bottle ( 0.33 L) - Tap included -

To reset pose, press N and set to 0 all rotations, so you can align them to axis.

Simple "glass" material

Subsurfs are not applied, so you can set datails.

Playing with light, you can have different effects on tha plastic material. Use un environments Hdri texture for best views (not included).