These will make great balls for your clubs net bag at your practice sessions.  

Various brands and model names, most of which I would describe as a "club ball", meaning it's a basic cricket ball with maximum of 2 layers twine and cork with a cortex (bullet) centre (standard construction these days to reduce cost).

Could also be used for 20 over matches.

At a price of just £4 each plus postage (but before any ebay premium is added)