Large Size:inner diameter is 2.0cm,external diameter is 4.1cm
Small Size:inner diameter is 1.5cm,external diameter is 3.4cm
No heat, no electricity, no damage to your hair at all.
Create Loose Waves, Spiral Ringlets, and Classic Pin Curls.
It is washable and light weight, very easy to clean and store, can be reused for many time.