12 ENGLISHIf the coupling does not reach or fit securely onto themale thread of the tool, especially when installing a longflexible shaft, pull the outer casing further towards thetool while hand-turning the flexible core shaft so theshaft top well fits into the shaft slot in the vibration headand becomes fully engaged.1 2Fig.20► 1. Outer casing 2. Flexible core shaft5. Knock each of the three corners of triangularcoupling with a hammer a few times in random order tosecure assembly.Fig.21UninstallationFollow the installation steps in reverse order.Installing shoulder strapOptional accessoryWARNING: Always remove the shoulder strapfrom the tool while wearing portable power packs.Wearing multiple harnesses and straps may impairthe chances to take the equipment off quickly in acase of emergency and result in personal injury.WARNING: Do not use the parts for attachingthe shoulder strap for other purposes, such asthe fall prevention at high location. If the partsfor attaching the shoulder strap are used for otherpurposes, excessive load may break them and causeserious injury to the operator and person around/underneath the operator.CAUTION: Be sure to attach the hooks of theshoulder strap to the tool securely. If the hooks areattached incompletely, they may come off and causeinjury.CAUTION: Be sure to use the shoulder strapdedicated to this tool. Using other shoulder strapmay cause an injury.Hang the hooks of the shoulder strap over the hangingholes on top of the tool.123Fig.22► 1. Shoulder strap 2. Hook 3. Hanging holeOPERATIONCAUTION: Put the shoulder strap on theshoulder, and hold the tool firmly with bothhands.NOTICE: At the very beginning of operation, theflexible shaft tends to vibrate at a higher ampli-tude. The tool will restore the normal amplitudeafter you squeeze and release the switch trigger afew times repeatedly.Make sure to throw in and keep the vibration head stand straightduring operation. Use the tool within the effective vibrationranges at equidistant intervals. The effective air bubble removalrange is approximately ten times the diameter of vibration head.Fig.23