The half-round foam roller has a D-shaped design – curved side for muscle massage (similar to cylindrical rollers) targeting legs, back, shoulders, etc.; flat side specifically for balance training, core stabilization, and proprioception exercises. Therefore, the half-round roller is especially suitable for rehabilitation training, advanced Yoga/Pilates practice, and multi-functional home fitness. It is not a replacement for cylindrical rollers, but a complementary solution offering “massage + training” in one product. For brands looking to expand their product line and cover more training scenarios, the half-round roller is a highly differentiated option.