This article contains the Shark® Stratos® DuoClean Cordless Vacuum Troubleshooting Guide. This supports the following SKUs: IZ400UK, IZ400UKT, IZ400UKTSB, IZ420UK and IZ420UKT. Please note this also supports the refurbished models IZ400UKREF, IZ400UKREFB, IZ400UKTREF, IZ400UKTREFB, IZ420UKTREF and IZ420UKTREFB.