I needed such a fuse holder for connecting the daytime running lights with my father. The installation is simple, disconnect cables at the center and ends with fully insulated terminal lugs and intended for various inserts, because you can use various flat fuses depending on use. I have the fuse holder now not needed, because in the vicinity of the relay I have my power of wiper motor fetched and is indeed protected. So I for later installation already are what is needed.