ICON 1/2 Drive Ratchet with Comfort Grip (PN 56341) 8x1 Gridfinity holder. The ratchet head is just a hair under the gridfinity width so I was able to keep it 1U wide.
Designed to be a close match for other ICON ratchet holders created by Geoff (on MakerWorld).
The author marked this model as their own original creation.