Piggyback Dovetail Assembly: Come with mounting brackets and a Losmandy style dovetail for mounting accessories on your CDK 14, 17, 20 or 24 Optical Tube.
Note: For CDK17 users-
170990 - is for the current CDK17 design with 10.24" of backfocus
170991 - is for the original CDK17 design with 8.81" of backfocus
Buy risk-free: When it’s time to trade up you’ll get the most value for your used gear.