I have been using this plank on a scaffolding stack rather than on trestles as it is intended - so I can't really comment about it for \"normal\" uses. As for its adjustments, the wing-screws that \"lock\" its length work fairly well, although I've seen them get loosened by something brushing against them. If I attempted to tighten them more, they appeared to deform the side of the rail, so I avoided that. Then there is a provided nut and bolt - which apparently is installed as a \"stop\" to prevent full compression of the plank. However, the proper use and effect of this \"stop\" remains unclear. And then there are the Velcro end straps, whose purpose SEEMS to be to secure the ends of the plank to the trestles - but just how to make that attachment is a puzzle - because the straps don't seem to be oriented to allow any practical strapping to a trestle... and they don't seem strong enough to secure the plank, anyway. So, all these \"safety features\" don't make much sense. That said, the plank itself is very rigid, fairly lightweight, and in several ways makes for a more stable platform than the (more expensive) scaffold-specific platforms. The downside (for scaffold use) is that the plank is taller than the scaffold platforms, so using them side-by-side creates a tripping hazard as well as uneven footing. Also, in order to avoid the plank \"kicking off\" of the scaffold framework, I added a 10\" U-bolt to each end piece of the plank, which then straddles the scaffold framework at each end of the plank, preventing it from moving end-to-end and falling off the framework. I imagine something similar could be used to \"capture\" the rungs of supporting trestles when using the plank for its intended purpose. Due to the 7' length of the scaffolding framework, I have used the plank extended only to 7', not out to its full 9' extension. At 7', the plank remains very rigid even under about 250 pounds of mid-span load. My only concern for using it as a solo plan