Consist of 12-18 convoluted tubules that arise from the rete testis and the base connects to epididymis (image A).
Some cells are tall columnar and ciliated (propel spermatozoa to epididymis) and some are short and non-ciliated (absorptive function) (image B).
May contain yellow-brown pigment.
Overall appearance is therefore of a "saw tooth pattern" of tall cells alternating with short cells.
A thin band of smooth muscle surrounds each ductule.