Magtech Shot Shell, 20 Gauge, 2.75" loaded with 26 3T (TTT) size lead pellets (.22") - known in the US market as size F, which is slightly smaller than #4 Buckshot (.24"), loaded by Magtech-CBC in Brazil for the international market, small gauge defensive or hunting load with high pattern density, velocity is 1250 FPS, hulls use a standard 6 point crimp for reliable feeding and function 20BSA