Extendable Bonnet Stay Prop. This is a quality non original modified design and absolutely brilliant for fast and improved access to the engine bay, for engine maintenance etc. Here's a link to a youtube video demonstration: http://www.youtube.com/watch?v=yz7v7QEDBxM Please note that it is only for indoor use in the extended position as there is a risk of the bonnet catching the wind if used in this position outdoors.Spring if needing replacing is part No BPF107