The Jelly arrived at around 6cm in diameter, which is large enough to be suspended and not jostled by most spray bars. Looks happy and is eating and growing.
Just make sure they don't spend too long in transit. The bell might be an odd shape if your temperature and salinity are different to what they are kept/shipped in, but that can quickly self-correct, and small tears on the bell gained in shipping will heal within days if your water's good.