21-Pin Unshrouded Header with 0.100" Pitch and Gold Contacts
The 77311-102-21LF: The header is through-hole mounted with a 0.135" (3.43mm) post length and an overall contact length of 0.465" (11.81mm), giving a 0.230" (5.84mm) mating pin length that provides good wipe for the receptacle contacts.
