With everyone being more aware of the difference between CMR and SMR drives, these ones are the WD40EFRX which are now called Red Plus.
You can see which WD drives are CMR and SMR via https://blog.westerndigital.com/wd-red-nas-drives/.
I bought the original ones back in 2015 and they are still going strong. My usage is my daily secondary drive, so store my photos, music, games, videos, etc.
Amazing how much the price has dropped, I paid $220 back in 2015. #cry
OOS?