Foldable and portable design Built with strength aluminum alloy for a lightweight yet durable roller trainer. Three adjustable rollers are mounted in a collapsible frame, making storage and transport easy when not in use. Quiet and smooth operation Matrix bridge structure evenly distributes force to minimize impact during use. Aluminum alloy rollers run quietly, with a noise level of 6075 dB. Mountain bikes tend to produce more sound than road bikes due to tire differences. Safe and comfortable riding Enhanced pedal design allows for easy mounting and dismounting, contributing to a safer and more comfortable riding experience. Broad compatibility and precise fit Designed to fit bikes from 24 to 29 inches, including mountain bikes, road bikes, and folding bikes. Front adjustment holes with measuring cylinders ensure a fit for a range of wheel sizes. Use scenarios Indoor training during bad weather or limited time, suitable for road, mountain, and folding bikes. for small spaces or home gyms thanks to the foldable frame and easy storage. Useful for testing fit and warming up across different wheel sizes (2429 inches) before rides.