This is a kind of self-telescoping crane slewing from the top,which is designed and manufactured by SCM.It can be rail-traveling, stationary or anchored stationary and internal climbing. 
We SCM company is a professional manufacturer of construction machines such as tower crane, construction hoist and concrete machines.
We have many types of tower cranes for you to choose.
The horizontal jib, luffing jib and flat head jib with stationary, inner-climbing and
tavelling from 1T-100T.
Welcome to contact me for more information.