The first is a Noga NF 1022 which has a stem for inserting into a collet in the Mill Spindle and is used for centering work under the Mill Spindle. The articulated arm has a fine adjust at the end of the arm (just before the indicator hole and dovetails) which seems appropriate for this type of arm. My main use will be for centering my Rotary Table under the Mill Spindle.
The second is a Noga NF 10433 which has a magnetic base with fine adjustment on the base and a short arm with hole and dovetail for holding both Dial Indicators and Dial Test Indicators. I use this on both the Mill and the Lathe. On the Mill typical uses are aligning the Vice etc and on the lathe it will be mounted on the Saddle for aligning items in the 4 jaw chuck and also for checking the alignment of my new lathe.
Both these Nogas are in the smaller sizes since both my Mill and my current Lathe ( Sieg SX3 an SC4) are on the smaller size. There are larger versions available for larger machines. They are readily available from USA suppliers and I imported mine to Australia from All Industrial Supply
The first photo shows a demo of aligning an object directly below the centre of the spindle. Note the fine adjustment at the bottom of the arm just above the indicator. Makes getting just the right amount of contact with the work a breeze. When alignment is correct rotating the spindle doesn't cause the indicator needle to move. Even with the small size Noga arm the range of adjustment is much larger than required for my size mill.
This photo and the next also show the Tormach quick change ER20 Collets that I routinely now use on my mill. My mill has a R8 spindle with a R8 3/4" collet which is the standard for Tormach tooling and changing tools with the Tormach Tool holders is a doddle. I suggest you check them out on the Tormach Site.
The next two photos show the Magnetic base model being used to align the Mill Vice with the x axis. The Indicator is held stationary fixed to the column and the vice is moved in the x axis to check the alignment.
In this case the fine adjustment is on the top of the magnetic base which allows adjustment without jiggling the indicator. There is no fine adjustment at the end of the arm, just the clamp for the indicator.
Are Nogas excellent tools YES
The fine adjustment screws have just the right degree of fine travel and sensitivity while the arm locking mechanism is smooth and secure. I originally had a cheap Asian copy of a Noga and while cheap it is not in the same league. It has been consigned to the bin. Are there other brands of similar quality indicator holders? I don't know. I have a Mitutoyo traditional type magnetic base and arm and it is no where near the quality or usability.
It is not often that one can find such quality tools at a reasonable price. The Nogas are a fine piece of kit and I would not hesitate to buy them again, buy more or recommend them.