Comparison : Item # 01-18A-20, 18A Series: .125 Board Hole x .125 Chassis Side
Item # 01-18A-30, 18A Series: .125 Board Hole x .125 Chassis Side
Item # 01-18A-40, 18A Series: .125 Board Hole x .125 Chassis Side
Item # 01-18A-50, 18A Series: .125 Board Hole x .125 Chassis Side
Item # 01-18A-60, 18A Series: .125 Board Hole x .125 Chassis Side