"These Tower 16mm oval conduit clips are too small and too stiff to accept the same brand 16mm oval conduit without crushing the tube. I had to clip them around a metal tube (monoblock tap spanner) and immerse them in boiling water for a few minutes, then allow to cool and set themselves in a more open position before I could get any use out of them – a right pain in the neck. Totally unsuitable for the purpose for which they are sold. The Tower 20mm oval conduit clips are much better mated to the Tower 20mm oval conduit tube than the 16mm offering. Why is this?"