Why Sealey...
Because it was the cheapest... by far. Teng do great tools, but the equivalent wrench is around £40, and I think the equivalent Draper one was over £30. Incidentally, I have two other Draper torque wrenches and they seem well built (definitely better than the Clark one from Machine & Mart).
The reason I went for the cheap one by the way is that I bought it specifically for the cam covers (although I did find-out since that also the throttle body bolts are 8NM), and I don't think that the absolute accuracy is important e.g. it could be 7.9 or 8.1NM, what is important is that (a) they are not too tight - bolting plastic into alloy to hold down rubber requires very low torque, and (b) more importantly that the torque is exactly the same for all bolts so that the covers don't get wrapped.
I have a good unit to cover the 10-80NM range, which is good for most bolts. I use the Clark for the wheel bolts which are 110NM, and this is good enough for that. I buy expensive tools when it makes sense to do so, but I already have three torque wrenches apart from the 5-25NM one so I didn't think I shopuld invest in a Teng wrench just for the cam covers.
Hopefully Sealey will fix it.....