This cheeky 4 oz bat, was given to me recently by my brother. He didn't bother to scour the depths of the internet looking at US or Dutch sports equipment websites. No, he apparently picked it up for £1 at the local 'Pound store'. Thanks Matt.
Seriously, I'm not sure if it would even survive hitting an indoor 'training' softball, let alone the real thing. However, I believe that it may be useful as a training aid. One can work on the batting stance and correct swing, even using it indoors without risking smashing anything valuable.