1.【Large Space Portable】The inner size of the aligner case is 3.66''L x 3.03"W x 1.26"H.The holder container is nice for mouth guards, night guards, orthodontic brackets, etc. Also, it is lightweight, easy to carry and suitable for travel. 2.【With Ventilation Holes】This slim holder with ventilation holes can generate airflow, keeping your holders dry and clean while stored.This means you don't have to worry about your retainers smelling bad after just a few hours of storage. Made of high quality food grade silicone, non-toxic and tasteless, strong and durable, BPA free, odorless.Provides a tight seal to keep dental braces secure.You can store your retainers safely and protect your oral health. 4.【Easy to Carry】The holder can be placed in your pocket or handbag and also comes with a lanyard.It can help you protect your holders well while you travel, go to work and eat. 5.【Multiple Uses】It can also be used as a braces case, denture case, headphone case, coin purse and jewelry organizer, etc.