I have been using burnishers for over 25 years now. I started in the print industry using them for rubbing down Letraset Type and pressure sensitive decals. The Chartpak Adjustable Burnisher always my default rub-down tool and I have kept a Chartpak in my artist tool box for rubbing down decals and shipping labels this whole time. You only use it once or twice a year, but when you need to make sure that item is securely rubbed down onto the surface, you want this burnisher.
The round tip is perfect for getting into tight corners or recessed areas, and the flat plastic end allows for even pressure over a large surface and flexible materials that keeps you from easily damaging the ink/surface of the item being rubbed down.
Only recently have I had the need to replace my old Chartpak. The retaining ring on my original burnisher eventually lost it's grip and sent the tension spring flying into the abyss of my studio. Upon receiving this new Adjustable Burnisher, i see they did away with the retaining ring and have molded the spring holder into the body of the Burnisher. WOOHOO! I should get 30+ years out of this new burnisher as long as I keep it in my tool box and out of the elements/sunlight (plastic tools do not do well against UV rays.)