The PMD1100A is a 1100mm length extension unit, which is suitable for the use on the floor tom side of the kit. It includes a J30TS joint bracket, which allows you to attach this unit to another vertical post. Horizonal Pipe Guide Line - Use this center mark on horizontal pipes to line up J30TS clamps. This will ensure that the angle of all toms and cymbals mounted on the horizontal pipe are consistent. Vertical Pipe Guide Line- Curved markings on vertical pipes, every 50mm, allow for easy and precise positioning of horizontal pipes.