Seasons' Greetings Y'all with a COVID-free 2021.

I discovered for finger strengths this handheld device called : https://prohands.net/collections/frontpage/products/gripmaster.

I think my problem with the Low E chord, is not strength, but flexibility. My left fingers won't open up in full wide range. Is there a handheld device for that ? In the mean time, trying my best to go 4 frets on low E chord, but wow, ouch, wow and ouch 😣