You bit for carbon fiber brushes / pickling brushes for cleaning of welding seams. You can erase with these brushes the tempering colors which are from the welding process at stainless steel V2A / V4A / AISI 206 / AISI 304 / AISI 316 or similar material which is quenched and tempered. These brushes are produced for electrolytic pickling and using with mordant. You use them with a power source. It is not important for our brushes if you use AC or DC electric current. These brushes are for cleaning / pickling of welding seams of the welding process by WIG, MIG, , TIG or for aluminum. With a useable fluid, you can use them also for passivating and marking. For a longer standing, you should use them in a PTFE-tube (PTFE) and let the working end as short as possible. These tubes are temperatures up to 160°C and also chemical resistance. Our brushes are produced of items which are used also in the electrical engineering. The protection cover of the brush is temperature up to 160°C and chemical resistance. Colour:Photo Color Material:copper + fiber type: M8 Package Contents: 20 x Brush Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.