Multisizer Ring Sizing Gauge for ring size 1 through 17, half sizes too.
I tested this ring sizer and it's accurate on my ring mandrel.
I also tested this by sizing my size 10 center finger and then placed a size 10 spoon ring on and the fit was spot on for me.

Measured my thumb as size 11 and a wide band in 11.25 fit perfect, so going up for wide bands is sometimes needed.
It's easier to adjust the tool while not wearing it, then slipping it on.

The key is to keep the flexible band round and slip over the knuckle. 

There should be a slight catch as it goes over the knuckle so the ring won't be too large and possibly fall off.

This tool should help in getting the correct ring size, but it won't be absolutely perfect. 

It can't replace trying a ring on in person and spoon rings can fit differently since some of them are wider than traditional rings.

The industry standard is to go up 1/4 to 1/2 ring size for wider rings, not all of my rings are wide enough for that standard though.

I feel this tool will be accurate within 1/2 ring size, which is a huge improvement over online ring sizing apps that need to be printed out. 

That's why I'm making this available for $3 free shipping, no tracking, just a stamp.

Also remember that finger sizes can change due to salt intake, weather, aging, or time of day.

Shipping is set to First Class Stamp, no tracking.  If you want to upgrade to tracking, please

send a message, the total cost of shipping with tracking is $5.

First Class letters are taking longer for delivery lately.

The best part is the tool is reusable over and over again, size all 10 fingers or share with others to get their ring size.

Directions are on the package.

Policies:

I aim for smooth transactions by sending the exact item, on time, and with great care.

Unless the wrong item is sent, there are no cancellations, returns or exchanges, but rings can be resized.

If there is a problem with your purchase, please contact me within 3 days of receipt, there is no time limit on re-sizing.

Orders are sent to the address provided so enter it carefully and double check for errors.  If the wrong address is given, you are responsible for locating the package.

I ship very fast, travel time is up to USPS.