Please see the above picture, I need a mechanism to connect handle to a controlled object below. While the handle moves from a to b (~10cm) the object needs to move from c to d (about 25 - 30 cm) and when handle moves back from b to a, the object needs to moves back from d to c. They are both restricted in a box 3 to 4 cm high. The mechanism should be simple and reliable for repeat operation. So I prefer rod, bar connection over gear or wire link. Is there something like mechanical telescopic rod on the market where you can extend the whole rod length by moving a little control distance?