Golf range finders have become so popular over the last few years that you might not realise up until recently they were not actually allowed to be used in certain competitions. The USGA which stands for the United States Golf Association had passed a rule to disallow the use of range finding devices to be used in Golf tournaments. This effected professional tournaments only as they then changed the rule to allow each local club to decide on whether or not they would allow the use of these devices in their local club competitions.
The PGA do not allow golfers in turn to use these range finding devices in professional competitions which is why you will not see the likes of Rory McIlroy on the TV using such a device. Nor are they allowed to use the GPS watches that are also quite popular. However this is not to say that the professionals are not using these tools in practice. According to www.dekoproducts.co.uk you can be sure that they almost certainly are using these devices to help them measure distance and also confirm how correct there judgement of distance is without the use of these devices.
Of course if you are just a casual golfer these devices are fine to use and most clubs will have a rule sheet up on the day of competition in which if prohibited these devices will be mentioned. It is only a matter of time however that these will be allowed to be used everywhere as technology eventually will become so popular that everyone bar the pros will be using them.
So if you are looking to improve your golf game these are a great addition to your bag and only cost less than the price of a golf club so it is not breaking the bank.