Nikon D3s and Sigma 150-600mm Contemporary above. This monopod is sturdy and very compact. Just not sure on the locking rings, locks well but doesn’t feel like a manfrotto or sachtler obviously, either way is extremely compact and great for travel.
I’ve used it to support a Nikon D5 and D3s with a newest Nikon 600mm f/4 FL VR and 400mm f/2.8 VR FL as well. Yes, it supports them without any problems. Baseball, soccer and MotoGP. Still going sturdy.
Sirui P-326 Monopod: http://amzn.to/2HNG3qE