Heavy Duty: trolley assembly is made of strengthened solid steel and galvanized properties, sturdy and reliable, impact resistance, smooth and noiseless, hard to break, deform, fade, rust and , withstand long term use What You Get: the package comes with 4 pieces of beam assembly, which can withstand a certain , to meet your using and replacement needs, bringing a lot of convenience to life Detailed Size and Load Capacity: steel plate aperture is 9/16 inch/ 14 mm, thickness is about 2/5 inch/ 10 mm, suitable for 1-5/8 inch wide and all 1-5/8 inch or taller strut channels; Single 4 wheel trolley assembly can hold up to 450 lbs Versatile to Use: the chain hoist trolley wheel is suitable for a wide range of different usage scenarios and is perfect for mounting on a ceiling trolley system or electric lifts, you can also use it in DIY projects according to your actual situation Stable Performance: 4 Pcs bearing trolley channel roller with welded bearings and pin shaft is safe and reliable, with tight connection and stable performance can smooth operation and reduce noise, Weight: 4.53711335196 Pounds, Manufacturer: Prterver