IMO, you should check the balance of ANY prop before installing it on an engine. Most composite props do not need balancing, but it's always wise to check. DO NOT sand one of these to balance it. Spray clear poly-u on the front side of the light blade. I also use poly-u on wooden props, although those may be sanded on the front side to balance. If a prop gently swings to the heavy side, it's ok to balance. If it drops to the bench with a THUD, return it.

Dr.1

PS I often take a simple Dubro teeter balancer with me to the LHS.