Brochure says up to 16 hours of run time. They have different sized tips that you can swap in to better fit your ears. If they use the audio industry standard nozzle sizes, you'll have plenty of options to figure out fit, as there are many aftermarket options for IEM sleeves (triple flanges, double flanges, olives, foamies, etc.). Many people can't stand having stuff in their ears for long periods of time, so that's something to be aware of; despite being a long time IEM user, I will occasionally still get itchy ear canals if using a worn out triple flange sleeve for an extended period of time. That issue can be partially alleviated with ear drops they make for hearing aid users who also have this issue. Note that pure plugs do not provide complete hearing protection, due to bone conduction.