Amazon.com
The Jasper Router Circle Cutting Jig is ideal for the speaker maker. Designed primarily for making smaller speaker cut-outs, particularly for tweeters and midranges, it can also flush mounting speaker drivers. Converting a plunge router into a precision circle cutting device, the jig allows the craftsman to make 120 different size cutouts in 1/16-inch increments. The cutouts range in size from 7-to-18-3/16-inches. Perfect for tweeters and small midranges, it cuts holes from 1-to-7-1/2-inches. Manufactured from cast acrylic 3/8-inch thick, the jig can be left on the router as a sub base, and be used with MDF, plywood, particle board, solid woods and plastic sheet. Made in the U.S.A., this circle cutting jig mounts directly to the base of 19 different models of plunge routers including Bosch 1615, DeWalt 621 and 625, Freud FT2000E, Hitachi M8V, TR12 and M12V, Porter Cable 690 series and 7539, Skill 1823 and 1835, and all Sears, Ryobi and Makita models.