A baseball bat may be legally owned. But I'm guessing you'd have a problem carrying one without a glove and ball or without being able to prove you were travelling to or from a game or practice. The torch in question is clearly not a bat and us marketed as "security" and mentions "self defence". This might contravene the Offensive Weapons Act 1996 (prohibition of the carrying of offensive weapons without lawful authority or reasonable excuse); but check more the definition of 'offensive weapon". I do know that you can be charged for "carrying an offensive weapon" if you have used anything "as" a weapon, even a fluffy pillow.

In short I think you'd be better off legally with a bat and torch rather than this thing.