The cokin p series bpw400a wide angle filter holder is a wide angle p type holder that attaches to the p type adapter ring similarly to a standard p type filter holder the cokin bpw 400a is an extra slim holder that helps to eliminate vignetting down to 20mm focal length this filter holder also features a vast range of adaptor rings including dedicated hasselbadreg b50b60b70 rolleireg vi as well as a universal ring and numerous dedicated accessories standard filter holders can carry t