ERA Implant Abutments are made out of titanium alloy and the "working area" is coated with titanium nitrite to make it more wear resistant. The abutments fit most major implant systems with the exception of Straumann's ITI system. The Abutments come in several heights and angulations to enable the practitioner to properly position the attachment. Ideally, there should be 5 degrees of divergence or less from abutment to abutment. It the implants are all placed within 5 degrees of divergence, then the task of aligning the attachments is very simple, you use the one piece 0 degree abutments and your in business. If the implants are out of alignment, the entire task of attachment placement is significantly compromised.