The NiSi Sigma 12-24mm f/4 HSM Art Series Adapter for NiSi 180mm Filter Holder made from aviation-grade aluminium and is compatible with the NiSi 180mm Filter Holder For Canon 11-24mm to allow the use of the NiSi 180mm System on the Sigma 12-24mm f/4 HSM Art Series lens with NO vignetting in a full 360 degree rotation.
This adaptor ring MUST be used with the NiSi 180mm Filter Holder for the Canon 11-24mm to allow the NiSi 180mm filter system to be used with the Sigma 12-24mm f/4 HSM Art Series lens.
