Foto4easy P200 Quick Release QR Plate for Manfrotto 500AH 701HDV 503HDV 7M1W 577 The QR plate can be used with tripod, rail, stabilizer and different devices, for Photography; Fast switching between different devices without replacing the qr assembly. This item is composed of a QR clamp adapter and a QR plate. Very durable,made of aluminium alloy Compatible for Manfrotto 500, 500AH, 701HDV, 577, etc.