Here is the one I use with my Masso and it works well.
The only negative of this keyboard is because it does not have a dedicated Home key it requires 2 hands and 12 fingers to do the homing with this keyboard. Doable but only just.
It is Wireless and I bought it when Dick Smith was closing down a couple of years ago. Unfortunately it does not have any identifying marks and I have been unable to find them online but if you see one 2nd hand it might be worth grabbing.
The label on the back says: dick Smith Wireless Touchpad Keyboard Cat: CN5086
$20 from Woolworths on special. I dont spend big bucks on these items as I have a habit of losing the mouse in the dust extractor. The only usable item left after it hits the impellor is the Battery. Most embarassing. The function keys are too small also.