• Levers in high-tensile light alloy (except the smallest size which is plastic). 
• Pulleys in zinc plated steel, aluminum or nylon.
• Sprockets in steel or hardened steel.
• Pulleys and sprockets have double-seal permanently oiled ball bearings. 
• Sliding head's orientation is adjustable, and it is made of low friction, wear-resistant polyethylene (dynamic friction coefficient of 0.06 on dry steel) with maximum operating temperature of 65°C (149°F).

These tensioners take up the chain or belt slack, and keep the tension constant without the operator making any adjustments over a range of approximately 45° (30° for the largest size).

• Can operate at temperatures above 100°C (212°F)(except TCP series).
• Uses special steel springs with an extreme high yield point and prestress, so as to maintain the pressure as constant as possible throughout the range.
• Can be assembled either from inside or outside of the machine (see the illustration below).