This operator can be used for most applications. The gate leaf is up to 16 feet. Opens with a 90 degree swing in 12 seconds & closes in 14 seconds. 800/900 Slow Speed Operator should be used in applications where the gate is over 16 feet & travels up or down a hill and/or if the gate frame flexes when reaching the end of travel. Can open with 90 degree swing in 17 seconds and close in 20 seconds. 800-900 Long is normally used in applications where gate is too large in diameter for normal mounting dimensions or where an insert cannot be mounted in the column. Can open a gate with a 90 degree swing in 12 seconds and close in 14 seconds.