I needed to have a powerstrip/surgeprotector hidden behind my Samsung TV. This uses standard VESA mounting holes (200mm x 200mm in example photos).
M8-1.25 x 45 mm: https://www.homedepot.com/p/Everbilt-M8-1-25-x-45-mm-Zinc-Plated-Steel-Socket-Cap-Recessed-Hex-Screw-2-per-Bag-803438/204281936
KMC 6-Outlet Surge Protector is what I got from Amazon. The side where the power button is has thicker base around it, hence the first printed piece is a bit longer. As a bonus, that piece also goes right over the power/reset button and prevents it from being accidentally pressed while mounted.