What size gear puller do I need?

I've been reading all the threads on mods for the mxus 3000w v2 4504, I decided to buy a gear puller.
This store here
http://www.princessauto.com/en/search?Nrpp=45&Ns=sku.price_listPrices|0&Ntt=puller
Is like the American Harbor Freight store.
http://www.harborfreight.com/catalogsearch/result?q=Jaw+Gear+Puller

Do I just measure the diameter of the hub, and thats what I buy?
They have an inch specification (2", 3", 4", 5", 6") along with either a dual or triple jaw.

I asked myself this same question a while back and tried to find an answer through searches but never did. Finally I just said frock it and http://www.amazon.com/gp/product/B000NPUKB6/ref=as_li_tl?ie=UTF8&camp=1789&creative=390957&creativeASIN=B000NPUKB6&linkCode=as2&tag=xbnijgbr-20&linkId=E4226NVEPGP2IUNQ bought this. I got the three jaw versions, seems logical unless you are dealing with an oddly shaped object, seems likely that the three jawed ones are probably a bit safer to use as well. I've used all of these at various times and was so glad I just got them all. It'll be pretty obvious with the set which size you want to use when you try to line it up.

After a little searching I found the outer diameter of your motor to likely be around 240mm. So If I had to guess, I'd guess you want the 8" or 10". http://www.amazon.com/gp/product/B002O16UHK/ref=as_li_tl?ie=UTF8&camp=1789&creative=390957&creativeASIN=B002O16UHK&linkCode=as2&tag=xbnijgbr-20&linkId=QVT7CWI5DJFR7DSI I've never used a 10" version, it's more costly but I am guessing that is largely due to supply and demand. So if you could, I'd probably locally source a single 8" version if you are looking to go with the cheapest route. You might just take the motor with you to a local store, open a box and see how the tool fits if you can find these locally, or look into a stores return policy.

I measured, eyeballed really with tape measure. 8-9" diameter.
But if you say its 240 Millimeters then thats 9.4488189 Inches so I was close.

So what a 8" puller, is that when the jaws are fully extended?
Or is that the length of the pivotal arm.
HF website states

Handles gears or bearings from 6 in. to 10 in. diameter

Click to expand...

My first instinct was to buy the 4pc 8"/6"/4"/2" from Harbor Freight because they are cheap.
Princess Auto, local to me, starts at 6" for $42. 8" $75.
I emailed HF for a s/h price for their 4pc - Includes 3 in., 4 in., 6 in., 8 in. pullers for $30.
Shipping Weight - 9.68 lb.

6" puller should do er.

Can be the very cheapest kind, doesn't need to be automotive grade with a fine thread screw. Like from HF. Should be cheaper, bastards making you buy four pullers.

I bought an Oreilly 6" puller for 18 bucks a few months ago.
otherDoc