I purchased 1 (undersize) under the trial offer and put it in on my driver. Game changer for me. Very tacky and all it takes is a damp towel to clean off sweat and revive the tack. Played 2 rounds last week in +90ºF heat and +70% humidity this grip was outstanding, very tacky. There are not many option for people that use undersize grips. Ordered enough for 2 sets of clubs. May try the air installation this time around? Very happy customer.