HHIP 3900-0599 ER-50 Spanner Hook Wrench for ER Chuck Nut, 78-85 mm Go to amazon.com Related posts Top 6 best er50 chuck FeatureFits ER-50 Open(mm) 78-85OAL(mm) 240Hardened Tool Steel DescriptionHHIP Tools provides the finest quality tools and their goal remains in providing you highest quality products.