PIN PROTECTOR/ PIN-THREAD PROTECTOR/ "FEMALE" THREAD PROTECTOR (TO PROTECT A MALE THREAD).
A PIN protector has an internal Threaded area
BOX PROTECTOR
BOX PROTECTOR/ BOX-THREAD PROTECTOR/ "MALE" THREAD PROTECTOR (TO PROTECT A FEMALE THREAD).
A BOX protector has an EXTERNAL Threaded area