LEVEL UP - When you want to feel the burn, elevate your bicycle to any of the 3 levels the Saris bike trainer front wheel block grants you. Choose your preferred difficulty to fit the type of training you want. GO HIGHER - If you feel like reaching even greater cycling heights in your rides, this bike trainer riser is easily stackable without losing stability. Access 12 different leves of challenge by bringing another Saris climbing riser block into the mix. RELIABLE STABILITY - Manufactured with safety as its purpose, the Saris riser block for bike trainers makes sure your front wheel stays in place, so you can have a comfortable ride, free of extra movement and worries. STURDY AND SAFE - Made of composite materials that guarantee the durability of your wheel riser block. This bike trainer block is wide and solid enough to place your bike on it, while avoiding rocking or moving. COMPATIBILITY - Works perfectly with any rear wheel-mounted cycling trainers. The Saris climbing riser block is able to fit up to 2.2” tires in any of its 3 grooves.