Is this for mass producing for whatsminer units? I couldn't find any data length and width of this busbar they usually call it a copper sheet I suggest better buy it and measure it with your own I found Zeusbtc has this
https://www.zeusbtc.com/ASIC-Miner-Repair/Parts-Tools-Details.asp?ID=2521It's around $7 but the problem is zeusbtc does not sell 1 piece moq is 10 pieces but if you are looking for the same copper sheet check Aliexpress I saw a Busbar with the same appearance or check this
link it is a bit expensive compared from Zeusbtc.