Replacement for chokes in Dynaco ST70, Mk2, Mk3 and Mk4. 1 1/2 inches (40 mm) tall on 2 3/8 inch (60 mm) mounting hole centers. 55 ohms, 1.5 henries, 10% tolerance, 2500 volt DC hipot tested, 200 ma DC. New unit MADE IN USA by transformer professionals with decades of experience manufacturing high voltage transformers. Sunn Replacement Part# 3-10C C354 Dynaco Choke Replacement also Sunn 3-10C MADE IN USA c354$16.95 Triode, USA For Customer Service, Questions, Shipping, Ordering, etc., M-F 9AM-4PM CT 1-800-774-3201 Email us Anytime: questions@triodestore.com TECH SUPPORT is available 4 days per week: 9 AM to 4 PM CT Monday, Tuesday, Thursday & Friday Ph 1-800-774-3201 Or email: tech@triodestore.com