That's what I thought when I was trying to invoke the get out clause but my BCO was not having it. There are three types of SPD the Surge Devices website does explain the difference and has a handy device selector. The one posted is the recommended one for domestic situations with underground cables for fitting into Domestic Distribution panels (CU). It does not protect against direct lighthning strikes as it does not need to, but does protect against other causes of surges that could damage delicate electronics. I meant to mention that at present Toolstation is the cheapest supplier I have found @ £44 but do not expect to find it in your local store only available online.

Richard