Review on ALPHA MOTO Universal Motorcycle Vacuum Carburetor Synchronizer Synchronization Balancer Carb Sync Balancing Gauge | Compatible With Honda Yamaha Kawasaki Suzuki GS KZ XS CB 550 650 750 850 900 BMW by Ken Hamdan

For those who know what they are for, great. For those who don't, there are some very good instructions in my kit. I know what they are for. I received this item as described. Used them and they worked very well. A couple of rubber grommets failed, I bought others at a local hardware store. The set and counters are excellent! The rubber hose was fine (it will break eventually, but you can always replace the hose in a car). Metal adapters are good and work. Based on what they're made of and how many times they'll last before I need a replacement, I'm not sure. They seem a bit fragile, so be careful when screwing them in so you don't "cross the threads" even slightly! Hopefully if you do this your threads will fail, not the main threads in the carburetors, so you can still get the carburetor bolts back in. (Maybe that was an idea when they designed the adapters? I don't know.)