The 100 5D fits PCS 1, PCS 4, and PRS 7 Repair Stands with composite top tubes. After years of research and testing weve built what we consider the best shop clamp made. Its smooth, versatile and built to stand up to everyday shop use. Cam actuated adjustment system for quick entry, adjustment and exit Fully adjustable clamping pressure prevents damage to thin walled tubes Handy spinner handle speeds large size range adjustments. Grips nearly any tube from 78 to 3 23 76mm, including aero tubes. Narrow clamping jaws 2.77cm fit into tight areas or on short seat posts. Precision machined, die cast aluminum main body parts and high quality small parts. Durable powder coat finish. Soft, durable composite rubber jaw covers. Saddle cradle provides a perfect spot to temporarily rest a bike.