2Packs Compatible with Whoop 4.0 Bicep/Ankle Band, 40cm Adjustable Nylon Strap, Breathable Design for Fitness Training, Washable & Durable (No U-shape Frame)

Pros: It's a good value with both black and blue colored arm straps for Whoop 4.0. The material is thicker than the stock band with stronger elasticity. I find that I re-adjust the strap less because the material is thicker and less likely to slip or fold over itself during movement under clothing.Cons: The thicker material does make it more sweaty and somewhat less comfortable, as a trade-off. The stronger elasticity means you really need the length adjusted correctly and during the hotter months, I do find myself switching back to the stock strap, which also has rubberized grips on the inside, which this strap does not.I would recommend it. The clamp end snaps in nicely with the Whoop and the whole thing looks good. I think of it as a winter/cold weather strap vs the stock arm strap as a summer strap so that complement each other well.