Sorry for the late reply, I had a look at what I have. I started off with orange 3M 1100 Foam Ear Plugs [0], but currently gone through two iterations of Moldex Pura-Fit Tapered Foam [1]. My main purchasing motivator is the decibel (dB) rating on the product, which blocks more sound -- which is standardized with Noise Reduction Rating (NRR).

[0] https://www.amazon.com/3M-1100-Foam-Plugs-200-Pair/dp/B008MV... [1] https://www.amazon.com/gp/product/B000BYAP7I