I sent my new 6.4mm EP to Meade because the threads wouldn't take a filter. They sent me a NEW 9.7mm back . . . now I have 2. Rather than hassle with Meade, I will sell the extra 9.7mm for $50.00 (in plastic Bolt) or swap you for a 6.4mm Plossl or buy someones used 6.4mm (or close).