48020-07 230mm 65mm 40 N/mm // 229 lbs/in // 4 kg/mm
48020-03 230mm 65mm 30 N/mm // 172 lbs/in // 3 kg/mm
Looked up the spring part number in Ohlins info online:
https://www.ohlins.com/product/road-...2012-2016-zc6/
https://world.ohlins.com/app/uploads...Subaru_BRZ.pdf
And someone helpfully posted the list of springs and specs on a BMW forum, which this forum might block the URL of, can't remember...
https://f80.bimmerpost.com/forums/sh....php?t=1323389
So 2.56" diameter (65mm), 9.06" (230mm) long
Eibach and HyperCo are cheaper than Swift ($60-$70 each instead of $80-$90 for Swift) and are regarded as the highest quality springs you can buy as a consumer, but their metric diameters are less comprehensive than Swift iirc.
@
Decep one of the advantages to adjustable damping is being able to adapt the damper to a different spring rate without needing a revalve, you can usually swap springs +/-50lbs/in without noticing a big change to ride quality even without adjusting the dampers. Different designs have different ranges and different people look for different things, I think there's a couple posts on this forum about swapping springs on the Ohlins and what rates they went with.