Arca-Swiss Conversion Set for Manfrotto 501 and 503 Pro Video Heads | 8.75" Extra-Long Plate

The Hejnar Photo M577-875 Conversion Set is a precision-engineered solution designed to modernize high-performance video heads with universal Arca-Swiss compatibility. Specifically engineered for Manfrotto systems utilizing the 3433PL (501PL) mounting plate—including the 501, 503, 3433, 3460, and 3465—this set features an extra-long 8.75-inch plate for maximum balancing range. This high-quality interface facilitates precise positioning and stability when switching between heavy cinema and telephoto rigs.

SAE Technical Specifications

Detailed Installation Instructions

Modernize your video head in just a few simple steps using the included hardware:

1. Secure the Adapter Plate: Slide the Hejnar 8.75" adapter plate into your Manfrotto head just like a standard 501PL plate.
2. Position the Clamp: Utilize the provided alignment pins to set your preferred orientation (parallel or perpendicular) on the extra-long plate.
3. Final Assembly: Tighten the clamp to the plate; the precision pins and stainless steel hardware prevent any accidental rotation under heavy camera loads.

Quick Overview & Key Features

• Maximum Balancing Travel: The 8.75" plate provides significantly more travel than standard plates, essential for balancing front-heavy cinema rigs.
• Modular Versatility: The 3.25" Arca-style clamp can be detached and used independently on other equipment.
• Precision Build: CNC-machined from 6061-T6 aluminum with rounded corners and edges for safety and gear protection.
• Zero Rotational Play: Milled registration ensures the clamp remains perfectly aligned with the head's axis even under extreme payloads.

Comprehensive Product Description

The Hejnar Photo M577-875 Extra-Long Arca-Swiss Conversion Set is the ultimate solution for professional videographers seeking the modular stability of the Arca-Swiss ecosystem combined with the fluid control of Manfrotto video heads. By converting your 501, 503, or 577 series head, you eliminate the "play" often found in stock sliding plates, ensuring your micron-level gear adjustments translate perfectly to your final capture.

The heart of this kit is the extra-long 8.75-inch adapter plate, which provides a massive surface area for balancing heavy professional payloads, such as cinema cameras with large matte boxes or long telephoto lenses. The integrated safety stop relief grooves provide a vital fail-safe, stopping an Arca-type plate from sliding out if the clamp is accidentally loosened.

Proudly made in the USA, this component provides the structural integrity and technical excellence that defines Hejnar Photo gear, making it a superior alternative to mass-produced adapters from competitors like Really Right Stuff or Kirk. It is a robust, intelligent investment that modernizes your existing support architecture for ultimate reliability across all your tripod and monopod rigs.