The given diameter refers to the inner diameter.The silicone hoses we offer are made of the best quality silicone, reinforced with a quadruple braid and spiral steel wire.They are very resistant to high temperatures, while being flexible at very low temperatures (-50 ° C ÷ + 180 ° C, periodically up to + 250 ° C).They have good mechanical properties and are extremely resistant to tearing and wear. It resists the effects of oxygen, ozone, weather conditions, UV radiation and infrared light.Due to their properties, silicone hoses are used in turbocharger inlet systems, cooling systems, etc.