surprisingly good ball vise I plan to use for engraving.I would rate this as a very good value comparable to the units costing $400 - $500.I've received this ball vise from the company dbm-inc covered in a light coating of oil, that only took 60 seconds or so to wipe off.The vise was well packed and I am glad it had the protective oil coating so surface rust didn't form while it was on the distributor's shelf. It arrived 5 days after ordering. I'm on the west coast, faster than what was estimated.There is a rubber support ring that the ball vise sits in, which is dry, not lubricated, so that it keeps the ball vise from rotating or moving. The top half of the ball vise rotates easily or can be locked as one chooses by a locking nut on the side of the ball vise.The top half rotation is very smooth, almost like it's rotating on ball bearings, but I don't know this for sure, it's just my description of how smooth the rotation is. I did have to unscrew the rotation lock nut a couple of extra turns to allow the top third of the vise to rotate 360 degrees freely.The hold down / pin accessory kit seems like it will work but some of the parts appear to be chrome plated and I worry that the plating might come off. This should not be a deturent for me as I see the value in the ball vise and in the worse case scenario I can make my own hold down pins and is why I rate this vise 5 stars. Again this is just my observation of the hold downs, not from long time use.UPDATE: the vise does have ball bearings in it for the top half to rotate. I took the 'locking' nut all the way out and the top half of the ball vise can then be removed. One does not need to replace the grease, but I did just because I had some waterproof grease for my bicycle at hand.