The insulated elbow is used when offset is required. Locking bands must be used on all elbows. A maximum of 6 feet is allowable between offsets. Elbow is fully insulated and can be used at the same 2-in clearance chimney lengths. Elbow support must be used with all offset installations. Elbows do not have locking ridges and can be rotated to attain optimum positioning offset, and allow the chimney to return to correct vertical alignment, prior to installing locking bands.