We added this (along w/a SHIP'S WHEEL) at the end of a long process of building the play set. It was a NICE ADDED TOUCH!! I chose a yellow item, to accent the yellow on our play set, and I'd read the reviews before ordering. It is good quality plastic and and I have had no problems w/it slipping. This detail really adds allot, my daughter gravitates to this periscope allot (even before we built the play set!=) We added it to the "LOOKOUT" at the upper deck on her play house...it faces our LAKE and WOODS and she likes to go up there and look around and see things! We JUST FINISHED OUR PLAY SET (* The picture attchd is from yesterday!!) & TODAY SHE LOOKED Through it AND SAID "I SEE FISHIES!" so cute!! If you were choosing btwn this and a wheel, I would go with this! It fascinates the little ones! (I was worried my 3 yr old would be confused that what she is seeing is lower then what she is pointing at-you know, NOT like a telescope-but she enjoys it just fine, and I'm sure she will continue to look thru it! She likes to turn it and look in diff.directions too!=) ***AWESOME ADDITION!! ADDS WHIMSY AND FUN!! GET THIS (or a telescope) before you get a WHEEL!! ** GOOD QUALITY PLASTIC=) Hope this helps!