Prop pictures here at iboats are facsimiles and have no real indication of the actual prop.
The description should be accurate. If you look up your motor/drive you will find dozens of props.
Probably 90% of these props will have a "rubber" sleeve with the "hub" pressed into the prop.
The purpose of this is to cushion the drive if the prop contacts something hard.
Diameter I believe up to 16" are available. And if listed for Alpha 1fits all alpha 1 drives
Some props have a removable hub that makes a prop a little more versatile.
If the prop is listed for say a Merc and has a removable hub,if the prop is also compatible with a Evinrude you can buy a hub
for that line of props to fit an Evinrude.
If it is a Merc prop it should have the Merc number beginning with 48 and usually ending with the pitch.
The other numbers indicate blades,material; etc You can find good buys on craigs and ebay Ebay does have sellers history
I do like to ask a couple of questions to see about communications and some inkling of the seller.
If I was buying a prop today I would use iboats and get an aluminum Solas Amita or Rubex.Rubex is the same prop with a removable hub.
Aluminum is about 1/3 the cost of a stainless prop.A carefully selected al prop can be completive with a ss prop.
Your present prop size,lightly loaded wot rpm and gps speed will help us help you decide.
Also need boat size and type.