Manfrotto 577 Quick Release Adapter with 501PL - photo/video - by owner - electronics sale - craigslist
Amazon.com : Neewer Rapid Connect Quick Release Sliding Plate Camera Mount with 1/4" and 3/8" Mounting Screws for Manfrotto 501HDV 503HDV MH055M0-Q5 : Electronics
Manfrotto 357-1 Rapid Connect Adapter with 357PLV-1 Camera Plate - Stewarts Photo