Grundfos insulation shells designed for thermal insulation of pump volutes in both heating and cooling systems. Compatible with UPSe 26-99 F, UPSe 26-150 F, ALPHA 26-99 F, and ALPHA 26-150 F circulator pumps, this service kit ensures a precise fit, improved energy efficiency, and reliable performance. Engineered for durability and easy installation, this is a genuine Grundfos spare part .