DTM Quick Change Holders. (1) H90-B8A – 1 Boring Bar Holder. (2) H90-2A – 3/4 Turning and Facing Holder. Delivering Quality Parts Since 2007. With Fast and Reliable Service. We strive to supply our customers with a consistent source for quality tooling and industrial supplies at a fraction of retail pricing. In the event a mistake is made, we will take the necessary steps to resolve the situation.