75mm CNC Lens Tripod Mount Ring for Samyang 24mm f/3.5 ED AS UMC Tilt-Shift Lens | eBay
Samyang Optics
Amazon.com : Tripod Mount Ring, Camera Lens Support for Samyang 24mm f/3.5 ED AS UMC Tilt-Shift Lens and Rokinon Tilt-Shift 24mm f/3.5 ED AS UMC Lens, Built-in 50mm QR Plate for Tripod