Versaball shafts and washers

[Stormrider]

I've ordered some versaball ball top shafts from Groovygamegear. I've noticed that they also sell washers for these shafts. Now I wonder: are these washers any special or can I use a generic washer from any other stick such as those sold by Industrias Lorenzo? Do you know if these standard shafts fit the Versaball shafts or maybe the inner hole is too big? Is the quality of versaball shafts any good, and durable enought? There's not picture in their website.

[Stormrider]

I've found out that the versaball shafts have a diametre of 1cm, and the hole of the standard washers is 1,5cm. What about the washers from Sanwas and Seimitsus? I could get washers from these sticks. The hole of these washers looks smaller, isn't it?