The zefal sealant spray with mount is an absolutely essential product for commuters or those who rely on their bike this spray can self inflate a punctured inner tube and seals the hole at the same time no need to remove the tyre when you puncture just attach the hose to the inner tube valve and press the button youll be up and rolling in no time seals up to a 2mm perforation in the inner tube thats the size of a large thorn drawing pin or tack