It's a 148 by 12 with an Allen key head of a Giant Anthem.
I'd like one of those brand x ones with a lever.
How do I know which one I want?

https://www.wiggle.co.uk/brand-x-twist-lever-thru-axle-1?lang=en&curr=GBP&dest=1&sku=100994576&kpid=100994576&utm_source=google&utm_term=&utm_campaign=Shopping+-+All+Products&utm_medium=base&gclid=CjwKCAjwjbCDBhAwEiwAiudBy2b1L8WktbmhuVpy4bWfGU_MbtQOqFAU22IsCxVAh7aG3wJygA-KKRoCAccQAvD_BwE&gclsrc=aw.ds
Use something like this: https://robertaxleproject.com/lightweight-thru-axles/ to figure out the thread pitch.
There is a printable one around somewhere that I can't find, but gives a PDF to print out and line up to figure out the thread pitch.
Here we go:
Perfect. Thanks.
A cheap ebay thread pitch gauge is really handy if you regularly fix stuff.
You can get a cheap metric and imperial set for £5, so handy to be be able to order the correct bolts, axles, nuts etc
Is this a 12 X 148 or not?
Thru-axle DT Swiss 12/148 mm Boost TA Aluminum 173.7x15 mm