A vertically adjustable landing gear system for a trailer includes a pair of vertically adjustable lifts, a hydraulic motor having a pair of rotational outputs and a pair of landing gear drive shafts, each rotationally engaging one of the respective lifts and one of the respective rotational outputs to vertically adjust the lifts. The filter has a porous open celled ceramic foam body with voids separated by struts wherein a portion of the struts are densified with glass. The fabric comprises an open mesh scrim having a having crimped, heat-resistant organic fibers compressed thereon and held in a compressed state by a thermoplastic binder. The imaging device is removably attachable to the terminal device. The multi-excitation analysis includes making a given power port conduct a given current, and measuring voltages at other power ports for evaluating mutual couplings across different power ports. The seal material can be selected to be comparable with a wide variety of gases, liquid coolants and the like.