Pixco Hasselblad B50-67mm Step Up Ring Filter Adapter The B50-67mm ring adapter easily screws onto the hasselblad lens with Bay(bayonet) 50 lens filter mount, and converts the thread size of your lens to the thread size of any other 67mm accessory (such as filters, hoods, flashes and lens converters) The Bayonet to camera lens: 50 The female thread to filter: 67mm Made of high quality anodized black aluminum (metal). Compatible with: Filters, lenses, adapters, lens hood, and ect..