LiftMaster Chain Drive - 87802 Heavy Duty Chain Drive Smart Opener with LED Corner to Corner Lighting™ and Battery Backup

Use a tape measure and record everything in inches. Measure the finished opening from inside the garage. These measurements help us prepare your quote; have a qualified installer confirm them before ordering.

1. A — Opening width. Measure between the finished left and right jambs at the top, middle and bottom. Record all three if they differ.
2. B — Opening height. Measure from the finished floor to the underside of the header at the left, middle and right. Note any slope or uneven floor.
3. L and R — Sideroom. Measure from each side of the opening to the nearest wall, post or obstruction. Record the left and right clearances separately.
4. C — Headroom. Measure from the top of the opening to the lowest ceiling obstruction, such as a beam, pipe, light or opener.
5. Backroom. Measure straight back into the garage from the opening to the nearest obstruction along the planned track and opener path. Include beams, ducts and shelving.
6. Send your notes. Include these measurements, your delivery ZIP code, door model and photos of the opening, framing and ceiling with your quote request.

Before ordering: Track, lift, spring and opener choices determine the required clearances. Roll-up and specialty doors require their specific manufacturer drawings; there is no single clearance that fits every door.

Measure only from a safe position. Do not loosen or adjust springs, cables, brackets or tracks. Have a garage-door professional handle those components.