Thats not performance - but the style is holding the grips of your scooter all the time you ride the bike - why aren't they high quality and very nice ones? PIAGGIO made some leather grips distinguished by the Vespa GT and GTS, but they can also use universal on every motorcycle. These knobs are open on the sides. GT / GTS drivers use standard vibration absorbers to close the hole, when using these outlets on any other scooter it is recommended to order vibration absorbers with the knobs. Attention: sockets have 2 different inner diamteres, one is 26mm the other is 23mm. For example, for a P Vespa series, one handle must be full of foam and the other must work to enlarge the internal diameter by about 1mm. A little effort to assemble, but then you get that individual style!