LiftMaster Specialty Roller Cage Bearing Hinge - Flat to Gate, Flat to Post (Aluminum/Steel) Sold in pairs. Self-Closing Hinges which is equivalent to 21

which is equivalent to 21

profile dimension

Also known as:  012381777013

so gravity pulls it back down once it’s released

number of full-length posts (21' or 24') would depend on height of gate and how much length you want to put in the ground (we recommend at least 4-1/2' or more)

LiftMaster Specialty Roller Cage Bearing Hinge - Flat to Gate, Flat to Post (Aluminum/Steel) Sold in pairs. Self-Closing Hinges which is equivalent to 21LiftMaster Specialty Roller Cage Bearing Hinge Flat to Gate, Flat to Post (Aluminum Steel) Aluminum Body with Steel Yoke Heavy Duty Construction for Maximum Durability Dependable Roller Cage Bearing Design Even Weight Distribution Five Times The Weight Bearing Surface of the Nearest Large Hinge Largest Weld Surface in the Industry Easy to Fully Lubricate Specifications: Maximum Gate Weight: Up to 600 lbs. per pair. Sold in pairs. Pair (2 per Box) 4. 7