Reply to Potentiometer question

Does this look okay?

http://cgi.ebay.co.uk/ws/eBayISAPI.d...ht_3115wt_1305

They look like they've got metal shafts but I find that hard to believe at the price he's selling them for. I want to use them with this:

http://midi-hardware.com/POT32

(the manual states that 20k Linear Potentiometers are required...

should be okay?