This is a simple (but clever) idea. An adapter on a keyring – great for if you need air while out on a bike ride – it works from compressors found at gas stations and a myriad of other places. I’m buying this for my husband – he loves to do long rides on his bike and I’m getting good at that ‘worry about him slightly while he’s out for no real reason’ thing. He says he needs an adapter anyway (at least that was his reason for trawling amazon the other night) and the added keyring bit may stop him losing it. Check it out here