Overview Reviews Product Description This is a 69 mm extension tube that adds 21 mm of length. The male thread is 4 mm long. Product Videos Custom Field Product Reviews Write a Review Write a Review × 69 mm Extension Tube - 21mm Length - SFE-M69-021 Rating * Select Rating 1 star (worst) 2 stars 3 stars (average) 4 stars 5 stars (best) Name Email * Review Subject * Comments *