Designed to be used on this Aliexpress Buck converter and it might work with others but have not tested the design on anything other then this version

https://www.aliexpress.com/item/1005004532117488.html?spm=a2g0o.order_list.order_list_main.193.71411802UGJ1QY

Designed to attach to a 4040 Rail Extrusion 

Materials:

• 4 - M2.5 5mm (nuts optional)
• 2 - M3 8 or 10mm 
• 2 - M3 Tnut
• 1 Buck converter and USB cables
• 1 set of + / - cables to the PSU

this is a powered mod and anything performed is at your own risk its best to verify power prior to connecting anything to the converter.