An image sensor having image sensor pixels operable in multiple gain modes is provided. A web client application, such as a web browser, executes in the client device. The assemblies include hydraulic motors, couplers and fail-safe brakes. At least one set of the first and second heavily doped regions is formed in the well region between the drain region and the source region, wherein the first and second heavily doped regions of the first and second conductivity type, respectively, are stacked vertically from bottom to top and have a doping concentration which is larger than that of the well region. The boot is installed by: placing the bottom opening of the vertical portion over a protrusion to be covered; placing the base portion flat over the roof; pulling a top portion of a side edge of the vertical portion around the pipe so that the top opening of the vertical portion is adjusted to fit the pipe; and sealing the top opening of the vertical portion around the pipe.