Heres some examples:
http://www.earplugstore.com/earmuffs.html
Units like these work well on the range and construction sites. You can still hear until things get loud.
We use em for shooting, so I cant recommend a particular model for power tools.

In my shop, Im never surprised by loud tools...so I use a $3 pair of 3M earplugs on a lanyard, when needed.
Hangs around my neck,inside my shirt, when I aint using em.
http://www.lowes.com/pd/3M-Reusable-Corded-Ear-Plugs/3102561