***** **********Best Quality Guranteed. *****DN25; the length is 25cm; for outside diameter: 8cm; lens UV size is less than 55mm*****Dew heater strap is an essential accessory that protects your optical tube from excess moisture forming condensation on the corrector lens*****Cloth covered with foam insulation on outer side for maximum efficiency and performance*****Electrical interface: USB Power Bank is required for 2A*****You can control the temperature; Electrical interface; USB Power Bank is required for 2A; Dew - Not Dew Remover is a 5V charger power supply; maximum power < 10W