Comparison : Item # 1 BZP, Knurled Nut for fractional tube
Item # 2 BZP, Knurled Nut for fractional tube
Item # 3 BZP, Knurled Nut for fractional tube
Item # 4 BZP, Knurled Nut for fractional tube
Item # 5 BZP, Knurled Nut for fractional tube