- Locking system of the telescopic sections using a brass bushing which incorporates a particular design threaded bolt. The system denominated "Circumferential locking technology" (CLT) is practically locking the sliding tube on 360° simply by pulling the brass bushing through a minimum rotation of the locking knob (only 20°).- Each telescopic section is fitted with a special profile terminal aluminium alloy stopper to prevent the tube section coming out from the alu casting connector. Up and down movements are extremely fluid and totally safe, guaranteed by 90° angle provided on the stopper against 90°angle on the alu casting connector.- Anti-slipping system knobs realized by thread interruption both on the bolt and on the locking knob .- Alu casting connectors are securely fixed on alu tubes by special profile headless screws which locks the connectors with no slipping risk.