How is Glof scope able to measure distance

Question
just saw it from http://www.sourcingmap.com/professional-electronic-golf-range-finder-golf-scope-...
claims "The Golf Range Finder s precision optical instrument designed to find the distance between you and the flag"...

Answer
Jexxi:  "Laser rangefinders calculate the distance to an object by bouncing a laser beam off of the object and measuring the lapsed time until the beam returns. Since the calculation is based upon the return of the beam, it stands to reason that a more reflective object can be measured at a greater distance than a less reflective object. Readily available models are accurate to within one yard and have the ability to measure distances to reflective targets up to 1500 yards away - that's nearly a mile - and they're accurate under nearly any condition."

This is a quote from this site:  http://www.sideroad.com/Backcountry/laser-rangefinders.html

Fairways and Greens,

John
www.golfnutts.com