A knee joint assembly for an agricultural implement or a vehicle includes a relatively short knee casting with an apertured end of rectangular cross section which is inserted in a mating steel knee tube. Redemption of the voucher requires the mobile terminal to interact with a retailer’s transaction system. The sense amplifier may have two or more gain elements which can be individually selected to adjust the gain level of the sense amplifier. The user credential may be used to grant access to software andor to grant access to information.