The Pro-Loc Buzzer Bars get their name from Solar’s very own P1 sure-grip, 5-spoke knurled thumbscrews which cannot fall out because of our special mechanism.They also feature our original Pozi-Loc Alignment System with the now renowned P1 5 Spoke' designer grip too, for easy and positive tightening and removal or alarms etc.Milled flats on each inner section eliminate any movement when extended and 3/8” BSF threads mean they are compatible with all alarms and back rests.Plus, high grade Stainless Steel construction and Solar design mean the Pro-Loc Buzzer Bars will last a lifetime. That’s why we engrave the Solar logo on them.- Precision engineered, designed and manufactured in the UK- Pro-Loc stainless thumb screw width adjustment- 3/8”BSF thread, compatible with all Solar banksticks and most others- Solar Pozi-Loc nuts for perfect buzz bar and back-rest alignment- Engraved Solar logo- Flat underside profile on the inner sections so that the bars can twist/wobble when extendedSmall Buzz Bar Width = 180-300mmMedium Buzz Bar Width = 220-340mmLarge Buzz Bar Width = 240-360mm