Steel Telescoping Square Tube Combo Pack 1-3/4" and 1-1/2" Telescope Tube x 12" | eBay
GN 1422 Steel Telescopic Slides, with Full Extension and Self-Retracting Mechanism, Load Capacity up to 290 lbf | JW Winco Standard Parts
6061-T6 Heavy Wall Telescopic Square Tubing - Alcobra Metals
Amazon.com: 4PK Support Pole, Steel Telescopic Adjustable 3rd Hand Support System, Support Rod, Supports up to 154 lbs Construction Rods for Cabinet Jacks Cargo Bars Drywalls Extends from 49 Inch to 114