Not sold at retail, but you can browse SmallRig
Some links here are affiliate links. If you buy through one, Creator Gear earns a commission, at no extra cost to you.
Creators cited with this
DSLR Video ShooterYouTube, 744K followers“There are tons of Top handles out there but I opted for this tiny NATO Top Handle”
Watch the video at 5:33
Creators who use this also use

SmallRig V Mount Battery VB212
also used by 1 of them

SmallRig V Mount Battery VB99 Pro
also used by 1 of them
SmallRig V-Mount Batteries
also used by 1 of them

SmallRig VB212 V-Mount Batteries
also used by 1 of them

SmallRig VB99 V-mount Battery
also used by 1 of them
SmallRig Wooden Handle
also used by 1 of them