EACHSHOT CS-V500 Retractable Video Slider 50cm Dolly Track Stabilizer 1m Actual Sliding Distance Load Up to 8kg for DSLRs Twice as original sliding distance, conceptionally retractable. 8pcs Ball-bearings design, multiple adjusting way of sliding tightness. Sliding Stopper built-in. Super smooth transporting belt and track design. 1/4" and 3/8" threads built-in the bottom for connecting with tripod.