I phoned the sales number and asked whether they could get an HP part M17068-001 for a ZBook G8. The service manual says this is the part number for a "Service Cover". I placed the order on-line and the part arrived. I noticed on the box, before opening it, that I had been sent a "Top Cover" but with the same part number. I looked at the manual and guess what, the same part number is used for two different parts of the same computer! Clearly there is an error in the manual, so I requested a return from Lambda-Tek and the service agent told me they would not process the return as it was my fault. I have a £100 part that I do not need, in an unopened box. Lambda-Tek said they would do nothing to help resolve a problem despite this being a clear part number duplication in the HP documentation. My businesses had been using Lambda-Tek for years, but their attitude was far from a helpful customer service response. We'll never use them again. There are other companies that do the same as they do, and with much better customer care.