http://www.ebay.com.au/itm/Aussie-Be...RiWmub40LbMREw
Just select the 3x7x3...$1.49 is hard to beat lol (plus in Melbourne)
Or:
https://www.ebay.com.au/itm/19100000...YAAOSwySVZ8cdK - that's for 10 of them
Make sure your dimensions are RIGHT - use a caliper