tank magnet 36 causes the receiving magnet 34 to rotate which causes an indicator in the dial assembly 32 to move in a preferred embodiment the indicator in the dial assembly 32 is a pointer 33 as seen in fig2 a as can be seen in fig3 the gear housing 50 has two portions the first portion 50 a and the second portion 50 b the first portion 50 a defines a passageway 52 located along the axis 25 shown in fig3 a recess 54 defined by the first portion 50 a and adapted to receive a pinon gear 65 more specifically a pinion gear neck 68 the pinion gear neck 68 is inserted into the recess 54 of the first portion 50 a of the gear housing 50 and the pinion gear teeth 66 fit into a pinion gear tooth slot 56 defined in the second portion 50 b operatively adjacent the recess 54 the pinion gear teeth 66 are free to rotate in the pinion gear tooth slot 56 in a preferred embodiment the pinion gear 65 includes a pinion gear nose 67 the pinion gear nose 67 is free to rotate in the pinion gear nose notch 58 located in the second portion 50 b of the gear housing 50 see fig7 d the pinion gear nose 67 allows for easy assembly and smooth movement of the pinion gear 65 alternatively as shown in fig7 a and 7 b the pinion gear tooth slot 56 could contain a pin 59 protruding from the pinion gear tooth slot 56 and the pinion gear.