These tees do the job initially but are simply not up to the job. They split due to impact from the clubs after a short time in use. I have to put rubber washers in them to strengthen the point the string goes into the tee. After previous experience with these I bought three sets to see me through the winter. My only other suggestion is to carry some pliers with you to clean out the broken tees in the mat.
These are good if you play a course where matts are used for the tee off area however I managed to lose the blue tee on the 4th hole of the first round I used them! Blue was the perfect height for me so now the set is totally usless
Husband wanted these tees for his winter golf. As weather has beren so bad with us he has not yet managed to use them but they are certainly exactly what was ordered. Delivery was within a few days of ordering.