In reply to Mountain_addict_uk: I've tried them and then sold them, I think they would be better used for aiding than taking a lob on one. I fell on one and it ended up having to stay in the crack, you can not get them out once shock loaded, they just stick and they are wirey and so just bend when you try to push them up to lift out, even 15 minutes with my nutkey did sod all to lift it.
I don't rate them at all, but would imaging if your life depended on it then they would comfort you, and you have money to buy new ones after each lob.