This first version had no cord grips. The students used silicone sealant but water was able to seep in somewhere. They say it didn’t flood. I have since purchased cord grips, http://www.newark.com/jacob/50007m12pasw-f/cable-clamp-gland-polyamide-thrd/dp/15M6172?ost=1168781&ddkey=http%3Aen-US%2FElement14_US%2Fsearch. Like the ones you suggested, these are also IP68 rated, but a little cheaper. However, the cord grips from McMaster seem better since they have an additional o-ring, are available in many different sizes to accommodate different cable diameters, and have NPT threads.