During the design and development of the ISC STRYDER durability and functionality were at the top of the list of priorities. The foot ascender uses tried and tested geometry to provide a smooth upward movement and positive engagement on the rope. The spring has been meticulously trialled to ensure that it has sufficient tension - so as not to 'pop-off' - but to still allow the device to move freely without towing the trailing rope. The foot-lever can be used to open/close the cam with the other foot, and can be hooked over the body of the device to hold the cam in the open (disengaged) position. If preferred, the foot-lever bar can be removed, allowing a greater pivot range on the cam. This in turn allows the user to deliberately remove the rope from the device by using a kick technique with the leg and foot that the device is mounted upon.