The Master Models 1/350 USS Oliver Hazard Perry class frigate upgrade set consists of 2 types of item; 5 aerials and a barrel for the 76mm/62 DP OTO-Melara gun amidships. The aerials are machines to a fine, sharp point with an insulator at the bottom; the barrel has the cooling jacket and barrel sleeve machined in place. The aerials are used both fore and aft on the superstructure, with the rear ones requiring attachement to a larger plastic assembly.