The ZIGZAG Plus mechanical Prusik is suitable for use with double rope technique and in combination with the Chicane also for single rope technique (SRT) and therefore offers numerous possibilities of application. The same handles as with classic Prusik pulley system techniques allow efficient movement in the tree. The arborist can move evenly in the tree thanks to the precisely controllable chain that either allows the rope to run through smoothely or blocks the rope completely. The user can control the descent speed by changing the pressure on the spring-lever on the top chain link. The encapsulated ball bearing of the rope pulley facilitates easy rope feeding. The lower connection eyelet with a high efficiency swivel ensures the correct positioning of the device and also ensures optimum rope guidance within the device. The fall arrest device is approved for ropes with a diameter of 11.5 to 13 mm and a maximum working load of 140 kg.