Size is approx: 57.0 by 3.0 by 1cmThis is a neck strap with a length adjustment slider part that can be adjusted to your preferred length and a safety part that separates the strap when strong force is applied.- This product uses stainless steel. If you experience any allergic reactions or abnormalities on your skin, stop using it immediately and consult a doctor.- Do not give it to infants. There is a danger of accidental ingestion or strangulation with the strap cord.- Do not wrap the strap cord around fingers or any part of the body. This is dangerous as it may restrict blood flow.- Do not use the product roughly, such as running, jumping, or jumping from high places with a smartphone attached. Excessive force can cause the smartphone to fall and lead to accidents.