Hi All,

Assuming that this is an American model, a regular hose cap should fit 
perfectly, as long as it is the right diameter...  I know this only because 
mine was unscrewed during shipment and fell off during delivery.  I discovered 
that in order to replace it, at that time, I would have had to replace the 
whole sink drain assembly (really stupid situation) in order to get just that 
plug.  I went down to the local H/W store and got a cap that fit perfectly and 
voile'...

         Jon