I buy all of my slip leads through Raderk9. I include them in my training programs, every owner gets one. I've ordered several of the 4 ft and 6ft leads. My personal preference is the 4 foot with the loop handle.
Our trainer recommended this leash and it's the best we have. We lost one and got two more! My dog seems to be very comfortable with it and I love that he feels gently led instead of jerked around.