Sound Post Position Measurer & Chin Rest Screwdriver Set ① Violin Sound Post Position Measurer This measurer is for checking the relative position of the sound post and the bridge. It's convenient for checking the setup condition. ② Chin Rest Screwdriver (Stainless Steel / Wine Red) This is a dedicated screwdriver for turning the screws of the chin rest. It's a simple and easy-to-use tool. This set is useful to have on hand when you're concerned about the condition of your instrument. It would also make a nice little gift for violin enthusiasts.