Designed to fit 1.5ml, 1.8ml, and 2.0ml microcentrifuge tubes up to 11mm in diameter; 100 tube capacity (tubes not included). Great for storage, transport and organization; Each holder has 100 holes (11mm diameter each). Made from lightweight yet durable high density waterproof, non-scratching, anti-rattle, 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). Measures approximately 15" x 4" x 1".