Buster Roller TBar - Alternative to Barrie GagBomber recommends the Buster Roller Tbar as an alternative to the Barrie Gag. This is a kinder bit and achieves a similar result. The Bombers Buster Roller Tbar Polo Gag bit is recommended for horses that are built downhill. This is a very strong bit, with the highest level mouth pressure. The TBar is a specialisation which aids in turning, especially for young horses. Size note: the Bombers Buster Roller is a broken bit that bends across the top of