okay so there's many different types of dental hand pieces these ones are these turbines okay or thighs known as high speed hunt pieces this one is a doing a chumpies okay so it has a debate fitting at the bottom of the handpiece so when you're attached to NH coupling tallit okay the next one would be a cable and piece and again it takes its own difficuly which is a cable fitting you have the nsk hung pieces with a PTL fitting okay so all these different type of turbines have their different fitting you have an NS k QD which again to take his own unit coupling you have BNA again its own coupling Sirona with its own cooling as well and star these ones are the major manufacturers at UC okay you also have different connections that go straight onto the lead so you have a midwest fitting Humpy's okay which goes straight ly straight on till 8:00 and also you have boredom fitting which again screws directly onto the lead so there are different types of fitting can pieces attached to the lead the most common problems you have with your turbines is usually when they bearings stop rotating so for instance when you have the bear inside and you go to use it and the birds not rotating that's one of most common problems with your turbines so usually this happens because the lubrication so if you've not lubricate your handpiece enough and a bandage is here it