HeavyDuty Material 240GSM PE material blocks debris such as leaves and branches, keeping your pool water clean and inviting all season long. UV Protection Three layers of UV stabilizers protect against degradation under harsh sunlight while enduring temperatures from 30F to 135F with enhanced tear resistance. Efficient Heat Retention The advanced PVC material captures heat effectively, significantly minimizing water evaporation for a comfortable swimming experience even in cooler weather. Use scenarios Offseason protection: Use when the pool is not in daily use to block leaves and branches and reduce maintenance while keeping water clean. Sunny climates: UV stabilized construction helps resist sun degradation for longer service life when exposed to harsh sunlight. Cooler weather: Heat retention helps maintain warmer water and reduces evaporation for a comfortable swim in cooler mornings or shoulder seasons.