just been speaking to a guy that used to use the flex couple joiner on his quickdraw manifolds and he said after splitting 3 flex joiners over a full race season he went to the solid joiner and has had not an issue in the past 3 seasons using the stainless tube joiner. $5 for 20 joiners compared to $25 for 1 flex. this is why many including myself are using the stainless tube joiners., this hobby is expensive enough don,t you think ? save a buck for the same result.