A microwave photonics based signal receiving device includes a signal generation module, a first Mach-Zehnder modulator, a dispersion module, a second Mach-Zehnder modulator, and a signal conversion module. The presence of the interposing material and the thinness of the high-k material layers reduces or eliminate effects of crystallization within the high-k material, even at relatively high annealing temperatures. The gusset is deformable to allow the sealing body to move between a natural configuration in which the sealing body is on a first side of the flange plane, and a raised configuration in which at least part of the sealing body is on the opposing side of the flange plane, and wherein the at least one convolute portion biases the sealing body towards the natural configuration. The top and side portions form a gusseted foot canopy. The gas-fuelled engine lubricating oil composition exhibits good resistance to oil oxidation and nitration and improved corrosion resistance.