These types of Hydraulic Cylinders have multiple stage of stroke from a basic tube.  These type of cylinders are used where the minimum closing height is vary less and stroke/ open length is required vary high. So these cylinder has multiple stroke is single basic tube. These can be Single Action or Double Action (normally these type of cylinders are single action) these acted with hydraulic pressure and mounted in vertical positions and returns by their self weight, there will be sufficient weight on these cylinder to lowering or detracting it. These cylinders can be used in horizontal applications also where these cylinders can be retracted and detracted by Hydraulic oil pressure. These cylinders can produce full force (related to pressure and working area) when retracted but can’t produce full force when detracted due to vary small working area of fluid. These cylinders can be designed up to maximum possible stages and stroke length.

Some of the photos and parameter are given under for reference

1) Single Action telescopic Hydraulic cylinder
Number of stage                      3
Max dia of Base tube                140mm
Min dia of ram (minimum)         57mm
Total Stroke                             6170
Minimum length of cylinder        2330

2) Single Action telescopic Hydraulic cylinder
Number of stage                      2
Max dia of Base tube                140mm
Min dia of ram (minimum)        90mm
Total Stroke                            6500 mm
Minimum length of cylinder       4000 mm

3) Double Action Six Stage Telescopic Hydraulic cylinder
Number of stage                      6
Max dia of Base tube                200mm
Min dia of ram (minimum)        50mm
Total Stroke                            3200mm
Minimum length of cylinder       930mm