Stackable mounting collars feature two-piece construction with flats on two outside surfaces which are drilled and tapped for attachment to each other, along with a countersunk hole for mounting to any surface. Designed to combine rigidity and flexibility, collars provide a smooth bore to evenly distribute holding power and prevent damage. Available in bore sizes from 1/8" to 16" ID. Stafford Manufacturing Corp. P.O. Box 277 North Reading, MA, 01864-0277