If your looking for replacement earpads for your Steel Series Flex headset I suggest the below replacement from Amazon. My Steel Series Flex headset is a few years old and they do not make original earpads replacements. The headset has excellent sound quality and everything but the earpads are in great shape. I didn’t want to get a new headset if I could find earpads replacments that fit.
After searching online for a while I finally found an reddit post about someone that used a size 65mm generic replacement that worked well and had been using it for a while.
I found the below on Amazon and gave it a try for $5.99 with prime. When I received them they fit perfectly and good on the ears. It’s tricky to get the pads on, but you start at the notch on the headset and twist clocking wise or counter clock wise depending on how you started. Keep spinning the earpads around till there fully in the groves around the earpiece.
Replacement Earpads Leather Ear Cushions Spare Ear Pads Kit fit for Most Headphone Models: AKG,HifiMan,ATH,Philips,Fostex,Sony,Beats by Dr. Dre and More,Universal Diameter 65MM(1Pair Black) by SDGL
Learn more: https://www.amazon.com/dp/B07KKFZ338/ref=cm_sw_em_r_mt_dp_U_W8EWEbVZZBZFW
Below is a picture of the cushions on my headset: