Rubber Imported REPLACEMENT TEE TOPPER: This rubber tee topper is designed for use with the MLB Pro Porta Batting Tee (not included) as a replacement for a broken or damaged topper to extend the life of your batting tee EASY TO USE: Simply screw the tee topper into the batting tee post until tight for a secure fit that will last swing after swing HOLLOW RUBBER: The hollow rubber design ensures that this tee topper won't get in the way of your swing so you can practice hitting the ball clean off the tee DURABLE: Made from tough, durable rubber that is constructed to stand up batting practice season after season without tearing or breaking BASEBALL + SOFTBALL: This tee topper is compatible for use with baseballs and softballs so all hitters can practice and improve their swing