The Sirio Performer 5000 is a CB and 10m trucker antenna with 3/8 fitting. This antenna is capable of handling very high power and has a detachable whip during car wash etc.  

Special Features:

CB & 10m Mobile antennas  
Very High power handling capability  
Tunable from 27 to 30 MHz  
Protection from static discharges DC-Ground  
17/7 PH tapered stainless steel whip  
Whip detachable for car-wash
Electrical Data:

Type: Trucker Antenna  
Frequency range: 27 - 30 MHz  
Impedance: 50 Ω  
Polarization: Linear vertical  
SWR @ res. freq.: ≤ 1.2  
Bandwidth @ SWR ≤ 2: ≥ 2600 KHz (230 channel)  
Max. power: 1500 Watts (CW) continuous / 5000 Watts (CW) short time
Mechanical Data:

Mounting: 3/8"x24 thread male
Height (approx.): 2.08m / 6.8ft
Weight (approx.): 480gr / 1.06lb
Whip Length: 17/7PH tapered stainless steel 1.8m / 71in
Shaft: Stainless steel 200mm / 8in