They do work - Rifleman PXS Hearing Protection Earmuffs

They do block sound decently well and they are low profile. Naturally, this makes them tighter than is comfortable, and hotter than is comfortable since the foam touches the ears. They haven't fallen apart in a few months' use, which means they're decently durable.
Pros: Inexpensive, low profile
Cons: Uncomfortable

This review was written in the old system and had content requirements that are different than reviews written today.