Humanscale Monitor arm parts M2 upper arm, no ball head. See the details in the picture.
eBay
NB G60 Mechanical Spring Arm 27-45 Inch Curved Arc Screen Desktop Monitor Holder 5-16kgs Ultra Wide Monitor Mount with USB Port
Aliexpress UK
eBay
Adjustable PC Monitor Arm Support NB F80 Single Monitor Bracket Up To 30 Inches Computer Desk Mount Stand Adjustable Gas Spring
Aliexpress UK
2 x Humanscale M2 Monitor Arm White Silver NO VESA PLATES. The auction is for 2 pieces of the N2 Monitor Arms as shown in the photos. Marks and scratches on them. Maybe missing the plastic cover as shown in the last photos (please check photos)
eBay
Adjustable Universal Monitor Stand, Ergonomic Monitor Arm Desk Mount, Single Computer Stand for 13-32 Inch Screen with Clamp
Aliexpress UK
eBay
NB G80 F7 E7 Gaming Monitor Arm 32-60 Inch Curved Arc Screen Desktop 2-20kgs Ultra Wide Monitor Holder Mount with RGB Light
Aliexpress UK
Base has bolt inside and plastic cover can be removed to expose bolt holes into a desk.
eBay
Monitor Mount Reinforcement Plate Monitor Mount Arm Reinforcement Plate For Thin Glass And Other Fragile Table Tops Bracket
Aliexpress UK
As pictured. Missing one acrew I think but 3 of 4 still holds very firm.
eBay
NB NEW F80 2-9kg 17-30" desktop LCD Monitor desktop Holder Arm Gas Spring Full Motion ergonomica dual arm USB 3.0
Aliexpress UK
Used Humanscale monitor arm plus base plate/ clamp Please see the photos for details and exactly what is included If it's not in the photos, it's not included This has been used and has yellowed on the plastic base cover Sold as seen NO returns unless faulty Ebays delivery times are a guide only and not guaranteed
eBay
NB NEW H100 22-35" Monitor Holder Arm Gas Spring Full Motion LCD TV Mount 2-12kg dual arm clamp bracket
Aliexpress UK
Used but in full working order, fits up to a 27 inch monitor. Very good condition being sold due office closure.
eBay
S500 Aluminum Gas Spring Arm 34-49 Inch Curved Arc Screen Monitor arm for Samsung Odyssey Neo G9/G7 Large Display Stand
Aliexpress UK