For those who've not seen: http://magicbikepolo.com/
The 20% code works for bulk orders too (ends up being £9.60 a head I think) and John H has also said they could work out a price for larger orders.
I don't know how good they are, but if there's enough interest maybe we could coordinate a larger order? Quite a few people talking about getting new heads, moving to capped etc.
Weight is 90g, 63mm outside diameter, 51mm internal, 120mm long