Guardian CB-18 Anchor for Metal/Wood* The CB 18 Roof anchor is a 18 inch post permanent anchor designed for Metal and Wood applications. * The universal 16" x 16" baseplate of the CB anchor fits easily into most applications eliminating unnecessary headaches. * The CB 18 includes a durable galvanized finish to withstand the harshest weather conditions. * The post of the CB 18 extends past roofing substrate to keep the attachment point high enough so it's still accessible after the roof