Seco 6601-01 Quick Release Adapter – 1/4" x 20 The Seco 6601-01 Adapter provides a reliable connection point for standard survey equipment, supporting flexible mounting and accessory integration.   Installs onto Seco 6602 series rebar bolts or SVR or CR series Leveling Rods for quick prism mounting. Key Features • 1/4" x 20 thread compatibility • Enables connection of survey instruments and accessories • Durable and corrosion resistant stainless steel construction