The McCormick 3187484M1 is a genuine OEM piston ring designed for a bore of 91.49mm and a height of 2.38mm. This essential engine component ensures proper compression and oil control in various Perkins engines, including AD3.152, A3.152, A4.212, A4.236, A4.248, AT4.236, T4.236, T4.248, and AT4.212. It provides reliable fitment for a wide range of agricultural machinery from brands such as Massey Ferguson, Landini, and McCormick, covering numerous tractor and industrial models.