Do not tighten these things too tightly! The star knobs are way too sharp! Was digging into the skin on my hands! When I scooted up to the table my leg hit the star knob and it sliced into my thigh! Very dangerous! Be careful! Very delicate filament and too thin in certain areas. Couldn’t handle the stress of tightening up. One knob went clockwise the other turned counter clockwise. Both started to strip right away. I was disappointed to say the least. I immediately sent the owner a message because It just broke. I was informed that I could pay for another one because it wasn’t broken during shipment! That’s poor customer service in my opinion!