Brake Lever Barrel Adjuster Size Question

[Eric7]

I wanted to buy a barrel adjuster for my Rad Mini Step Thru brake lever. I think all the Rad bikes uses the same brake lever? 

I have a micrometer and I measured 9.17 mm which I have difficulty understanding.  I look online and I see 7mm adjusters, 8 mm adjusters and 10 mm adjusters but no 9mm adjuster and I am not even sure if a 9 mm adjuster would fit since I am measuring 9.17 mm.

Does anyone know which size I should buy? Is it some uncommon and not easily found size? It seems to be a tektro CL530 lever.  I just want to buy a few spares.

[Radding Along]

Tektro Aries series found on Rad bikes:

Lever adjuster:  M7 threads, 1.0mm pitch, 15mm thread length, 26mm overall length

$12 for 10 pieces:

https://amzn.to/3FQAWUU

Caliper adjuster:  M6 threads, 1.0mm pitch, 15mm thread length, 31mm overall length

$14 for 25 pieces:

https://amzn.to/3HqeYbI

[Eric7]

I bought some brake cables and it came with assorted barrel adjusters so I can figure out the one that fits.

My feeling is that the size of barrel adjusters that fits the original equipment brake levers is: 10mm x 26tpi.

The diameter of the threads is 9.44 or 9.5 mm.  But somehow they call it a 10 mm barrel adjuster.  I hope this information is useful for somebody.

[Radding Along]

I'm not sure if you noticed, but I listed the sizes above. And I assure you they are the correct sizes listed.

[Eric7]

I'm not sure if you noticed, but I listed the sizes above. And I assure you they are the correct sizes listed.

I respect you and I am thankful for all your advice and they have helped me a lot.  In this case, or in my case, maybe Rad switched suppliers on my bike vs yours.  I really think I need an M10 brake barrel adjuster which I got and it works.

The point is sort of moot now because I replaced the brake lever with a set ordered from Amazon.  The original brake levers were ordered from Rad on Dec 15 and I don't expect it to come anytime soon if ever.  Rad is short on parts.  At least the bike is functional.