First of the rubber straps arrived, bought a couple to try out. This was the most expensive one, complete PITA to fit and still not quite right, also the buckle is pretty poor quality. Not as good as my previous 20mm v6f strap I bought from a TD a few years back but then it was nowhere near the price either. Overall I would say not too bad and probably worth about the price I paid, still hoping (probably unrealistically) that the others are a bit better fit & finish.
Link here; sorry can't get link to work just type 'Silicone Rubber Watch Strap Original Quality Watch Bracelets Special for Tudor Black Bay for men20mm 21mm 22mm Watch Accessorie' into Aliexpress
Thanks for the review, do u have any closed up shot on the buckle? Thanks