The title sounds bad, but let me explain:

I'm shortly flying from LHR-DXB-SYD-AKL (on EK), and I want to bring with me an high pressure air blower (friend is bike nut, wants one and apparently UK cheaper to source than NZ). The blower weighs about 8 lbs (~3.6kg) and, well, I wonder if it looks a bit dodgy? The other alternative product is this smaller blower, which only weighs 3 lbs (~1.4kg). My friend doesn't care which one, and weight is not an issue. My only concern is if it will cause trouble if I place it in checked luggage?

Has anyone had experience with transporting these sorts of goods before? Do you think it will cause problems? Should I be taking a different approach?

At this point I'm thinking of buying the smaller one, and not locking the suitcase. I have TSA-approved padlocks, but they don't seem to make any difference when not traveling via the US (last year, security staff at MAD broke my TSA lock, and my zips!, to inspect the bag, so guess unless its the US it's not worth using).