Why?
1) diameter of 3 cm: Some manufacturers / vendors save on material, offer bars that have less than 3 cm in diameter, sometimes still in the set with their own weights. However, 3 cm are the more common measure, even with dumbbell bars. So there is the advantage that you can use the versatile weights without anything rattles or does not fit on the rod.
2.) star screws: I do not think much of locking rings must be tightened with a hex. That's in training something unwieldy, scratched / damaged also unnecessary to chrome plating. Locking rings with rubber coating for better grip as in this article are because from my perspective as the better choice.
3.) barbell in one piece: there are barbells, which consist of individual parts have to be screwed together. Without that I know this, just do not like my idea. With a barbell in one piece, just like here in this offer, I feel more comfortable ...
4.) length of 1.60 m: there are also longer barbells. This has confused me at the beginning of something. Here as well the other recessions have helped me here. Can confirm now: find the 1.60 m perfectly adequate. Use the barbell partially (misused) as a stretch for pull-ups (in combination with dumbbell stand) because a door bar in the lightweight / old way of doors / frames unfortunately eliminated from me. And here I find the length even in wide grip enough and comfortable.
Conclusion: buy :-)
