The SL 400 was designed to be the largest truck crane that could travel legally on the roads of neighbouring California without taking off the upper. The SL stands for Street Legal. At the time, the 180 US ton lattice boom 8470 American was the largest street legal truck crane. The largest telescopic crane was the 130 US ton 1300 Grove。
Jake’s designed and built the crane itself only after it had failed to generate interest from manufacturers. There are two boom systems – a 290ft (88m) heavy-duty boom, or a 350ft (107m) high light boom.