The Dual Lock recloseable fastener system from 3M has been put to very good use by Glasgow based advertising media specialist, Spedian. The company has developed a rapidly changeable system of reinforced vinyl advertising panels for rigid-sided articulated trailers and other vehicles. The panels, which can be changed in less than one hour using equipment purpose built for the application, allow fleet owners and advertisers to vary their messages and more precisely target their audiences.At the heart of this system is a framework of 3M Dual Lock recloseable fasteners, permanently attached to the truck sides in a pattern that matches a similar grid of Dual Lock on the reverse side of the advertising panels. A special installation tool allows the banners to be unrolled along the vehicle side with millimetre accuracy. The fastener system is available in transparent form, so it is virtually invisible on the truck side when no panel is being carried.The panels were tested for aerodynamic and mechanical loading at MIRA's facility in Nuneaton and have been proved at simulated speeds and distances of up to 140mph and 200,000km.3M Dual Lock uses a network of tiny micro-replicated polypropylene 'mushrooms' bonded to 3M VHB acrylic adhesive tape. The mushrooms interlock positively with each other to give a secure, precise snap fit that can be removed and re-fastened hundreds of times.