This is a handhold to be bolted onto an indoor rock climbing wall. I printed it out with ABS and experienced some warping issues because it is such a large part. Widget tells me that printing with PLA may solve the warping issues so I'll try that next. I haven't actually tried this on the wall yet. I'll let you know how it goes...This hold is designed to accept a standard 3/8" socket head cap screw. Simply add a washer and bolt to the wall. WARNING Rock Climbing and Indoor Wall Climbing are inherently dangerous - you could get seriously hurt or die. Don't climb without first getting proper instruction from an expert. Don't try to use this design unless you're willing to assume all the risks associated with its use.