Check the listing for details. CDV-717 Radiation Detector Zero Selector Switch / Knob Replacement / Repair Part. Condition: Used. Listed at 9.99 USD. CDV-717 Radiation Detector Replacement / Repair Part: Zero Selector Switch / Knob and Set Screw. Includes knob/screw only, no detector is included, detector photos are for example/confirmation of model type. Let me know if you have any questions! Thank you. Items are stored in a smoke/pet free home. I do my best to ensure that items are described accurately and shipped safely. If you have any issues with your order, please contact me before leaving negative feedback and I will do my best to work out any problems. Shipping: Items are typically shipped via USPS or UPS Ground. Sometimes I use recycled packaging in good condition for shipping, this brings down the shipping cost to you! Some items may require shipping to an address other than a PO Box and large/heavy items may require an additional shipping fee to Alaska/Hawaii/Puerto Rico. Return Policy: No returns/cancellations accepted. Please be sure you want the item before purchasing.