How Tumble Dry Low Works
The dot inside the circle-in-square sets dryer heat: one dot low, two medium, three high. Low heat exists for synthetics — polyester and nylon soften below high-heat thresholds, and elastane (spandex) is permanently killed by one hot cycle (the yoga leggings that "shrank"). Low takes longer and costs less regret. The crossed circle means no tumble at all — hang or flat.