6 to 18 Foot Super Duty Series 9000 Dually Pole with Dual Locks (3-Piece) These super duty poles have a dual lock assembly using the nylon Outside Lock and the patented Cam assembly. With this pole you can lock both external and internal locks for more locking power on jobs that demand the most. The tubes are made of the heaviest drawn aluminum tubing in three-piece pole combinations. They all come with the larger drain holes which help make the poles lighter in use. Nylon Internal Cam or NIC is Skimlite's newest design of locks. Designed to work like conventional cam locks yet stronger and more durable. For over 50 years, Skimlite has been dedicated to supplying top of the line equipment made 100% in the USA. Skimlite believes products should be made to last. Quality pays for itself!