Keuffel & Esser 4161-3 10″ Plastic Polyphase Mannheim Keuffel & Esser 4161-3 10″ Plastic Polyphase Mannheim – 023720Keuffel & Esser 4161-3 10″ Plastic Polyphase Mannheim – 025172Also See:68 1576 (4161-3) 10″ Modern Polyphase (Jet Math)