I think it'd be helpful if the dimensions / size of the item was included in the description.
Oops! Looks like the dimensions are only displayed IF the seller fills in the field (?).
Glad you figured it out johnchampion. Yes, dimensions are not a required property, so they might not be present on all posters.
How to delete Dimensions ?
If you clic on, you have to type something. Impossible to get rid of this. I've type 1, but I want nothing.
It is very difficult currently to get rid of them. What can work is:
1) Click on another field like 'Link' or 'Date'
2) Actually add data to that field! Use wrong data if necessary, just to have something in there.
3) Go back to the dimensions and change the unit!
4) If the field has a yellow background you may be able now to remove the value.
5) Click in another field again, ie. to delete the intentionally added wrong date or link.
I updated your Alien Germany entry with that i.e. now.