Stiebel Eltron's 227665 Summer cartridge is a carbon heating foil designed specifically for the LSK 303/403 series. Its primary feature is efficient heat delivery for seasonal applications. Typically, this product is used in residential or commercial settings to enhance climate control during warmer months. https://elecena.pl/product/28898760/stiebel-eltron-227665-lsk-303-403-summer-cartridge-heat-transfer-alternative 2025-06-03 https://elecena.pl/product/28898760/stiebel-eltron-227665-lsk-303-403-summer-cartridge-heat-transfer-alternative 2025-07-12