The 301A028-25-0 from TE Connectivity / Raychem Brand is T shape, black color heat shrink boot with shell size 28. This heat shrink boot has 0.790" (20.07mm) to 0.402" (10.21mm) large diameter and 0.790" (20.07mm) to 0.402" (10.21mm) small diameter. This is elastomer, semi-rigid, irradiated heat shrink boot with length of 3.540" (89.92mm). Operating temperature range is from -75 to 150 °C (-103 to 302 °F).