Designed to fit 4ml vials up to 15mm diameter; Includes 10 holders, 50 vial capacity each. Great for storage, transport and organization. Made from lightweight yet durable high density waterproof, non-scratching, anti-rattle, non-toxic black foam material. Note: Avoid halogens, strong oxidizing agents, benzene, petroleum ether, aromatic and chlorinated hydrocarbons. Easy to clean (can be washed and rinsed, top rack dishwasher safe). Each measures approximately 9.25" x 4.5" x 1".