3004 is similar to 3001... its basically a ball raced 3003 !

Theres a whole bunch in the same category, one will br dropped Im sure at least, if not two.

In order of cost/quality they go from cheapest to most expensive as

3003 -> 148 -> 3004 -> 3001.

I would anticipate that the 3003 and the 3004 will be the long runners.

3004 packs more punch at 6V and is rated for it... not sure if 3001 officially is.

Anyway !

Got prepared to go flying for the first time in months today and whilst the wind has dropped the rain is here ... bugga