Instruction: Output yes if the supporting document can answer the given question. Otherwise, output no.

Input:
Question: this hangers can be used in block walls?
Document: The nails usually go into plaster and dry wall smoothly, but in recent years they seem to be softer and some bend easily. Several reviewers have noted that the hooks don't seem to hold the stated weights. I believe that's true, but being very cautious, I've always used hangers that are rated for at least twice the weight of the item I'm hanging, and I've never had a problem with anything falling down or hangers coming out of the walls.
I've used these hooks to hang most anything matted and framed, large wall clocks, weather gauges, mirrors, and even wall mounted shelving. They hold fast and tight and can be easily removed if the need arises.Some of the product features are:* Nails when removed will leave small pin holes in wall* Museum quality picture hangers. * Nails are re-usable* Holds 5-100 poundsOOK Professional Picture Hangers are museum quality. Nails are re-usable and will not damage walls.
I used these to hang pictures on my walls which are plaster and lath - they work well. I recommend.
I have been using these for years and they are great. I live in an older home with plaster walls, so the cheap ones used to bend when nailing them in. Not these. I trust them to hold up anything. never failed me yet.
I used to use thumbtacks to hang everything on my walls. They weren't the best but they worked just fine until they fell down. My husband introduced me to these and they're fantastic! I can usually slip the very sharp tack into the wall with pressure from only my hand or steady pressure from a quickly available object--no hammer needed. They leave minimal damage in the wall and, unlike my thumbtacks, they're reliable. I'll use them for everything we hang on the walls from now on!
These hangers work well, my local hardware store does not carry this style. I do have plaster walls and this product does exactly what it promises...
I live in a building that was built in 1911. Our walls are plaster and lathe...and regular nail hangers pull out...or worse...damage the walls. These OOK hangers are fabulous for older walls...and work just as well in my bathroom which has modern drywall.I have a 40lb mirror hanging up in my bedroom...that has now been up for year number four.
I've been using OOK picture hangers for years and I prefer them to all others. They're attractive, don't tarnish, don't damage walls, are affordable and easy to use. But they're not perfect. Sometimes I encounter a hanger that doesn't have a hole punched all the way through, or the hole isn't big enough for the nail, wasting an entire hook. Another problem is that, although the nails are fairly easy to remove from one spot, they really can't be reused; they bend and the heads break off.
I am familiar with these hangers from my experience as a picture framer in New York. I used these for professional picture hanging.
The nails a sharp and hardened, when they get into the wall they cause almost no cracks.The hanger themselves make sure the nails go in the right angle.I used cheap hangers (the ones that come for free with picture frames), I like this product much better, worth every cent.
Answer: yes