Kirk lp 39 quick release lens plate for sigma 50 500mm f4 63 and 80 400mm f45 56 ex os apo
The kirk lp 39 quick release lens plate fits sigmas 50 500mm f4 63 and 80 400mm f45 56 ex os apo lenses it provides a secure quick release capability with arca style release systems including kirk arca swiss acra tech and wimberley