Welcome, and thank you for looking!One new Horolovar 400-Day Clock Temperature Compensating Pendulum Suspension Spring Unit 5E. The unit consists of a top block, fork, and bottom block attached to a Horolovar temperature compensating pendulum suspension spring. Included with our unit 5E is a removeable pin for the bottom block to accomodate newer clocks equipped with a pendulum locking device. If your Kundo clock has a pendulum locking device, a fixed pin bottom block cannot be inserted into the pendulum. With the included pin, Horolovar Unit 5E is interchangeable with Horolovar Units 5A, 5B, 5C, and 5D. Unit 5E also has an improved fork design which is lighter in weight and has a closed end that helps keep the tines from becoming bent. This unit is designed and manufactured by Horolovar to fit and allow for proper regulation of all Kundo ( Kieninger und O bergfell) miniature movement clocks. These are the Kundo clocks measuring approximately 9" from bottom of base to top of dome or case. If you have an older Kundo miniature movement clock that does not have a pendulum locking device, and you prefer a fixed pin bottom block, just let us know, and we will switch out the loose pin bottom block for a fixed pin bottom block. With your order, we will send you our detailed, step by step, color illustrated installation instruction booklet written specifically for Kundo miniature size clocks. It addresses all differences in pendulum and suspension spring guard designs that Kundo employed over the years, and includes easy to understand instructions for putting your clock in beat. Written by snoopyrb1, from his experience repairing and restoring anniversary clocks. Here's what our customers have to say about these instructions: 'Excellent instructions. Easy to follow and explained in great detail. Very nice job.' 'The instructions were very clear and useful! Before this, I did not touch any 400 day clock, and the suspension unit installation instructions was very simple to follow... Good job! ' 'Good info and was very easy to install.' Interested in a suspension unit for your clock, but don't see what you are looking for? If we don't stock it, we can assemble a suspension unit using genuine Horolovar springs that meets manufacturer specifications for nearly any mechanical anniversary clock, and include an installation instruction booklet that most closely matches your clock. We know anniversary clocks. Any questions, just ask! () We provide shipment tracking for all shipments within the USA! And shipping anywhere worldwide is FREE!!! This unit has been carefully assembled in a jig by hand by the professionals at Horolovar, guaranteed to be accurate in every respect for the clock and model specified. We want you to be happy with our products and service. Please contact us if you have any questions or problems. We feel you've done your share for a successful transaction once you've paid for your purchase. Why should you have to wait to receive your feedback? We leave positive feedback when payment clears! We will ship within 2 business days of receiving cleared payment, usually the very next day.