Spot the difference

[Bungleaio]

After a couple of nasty accidents at worksop yesterday I need some replacement turnbuckles, but can anyone tell me the difference between these, apart from the price?

50mm XH001 £12.72 - http://www.teamxtreme.co.uk/store/in...roducts_id=282

50mm S123 £6.84 - http://www.teamxtreme.co.uk/store/in...roducts_id=177

30mm XH002 £12.72 - http://www.teamxtreme.co.uk/store/in...roducts_id=283

30mm S124 £6.84 - http://www.teamxtreme.co.uk/store/in...roducts_id=176

I also need some of the M4 top links as I discovered all four were bent before I hit the track yesterday, does anyone know what length they are as DMS sell lunsford 4x18mm ones for £6.75, so they are a bit cheaper than the ones from extreme at £9.78

Cheers