Daitouge 2.5 Gallon Glass Jars with Lids, Heavy Duty Glass Storage Canisters for Food Storage, Set of 1

If I wanted to clamp a small light fixture to the rim to use as a nano planted aquarium, what is the width of the rim so I could measure for the clamp

is the handle and lid one solid piece or is the handle a separate piece fastened on somehow?

Is this dishwasher safe?

could these hold around 20 lbs 9.07kg of bird seed or more like 10-15?