Add to Cart Quick view RL Drake R-4C FL-500, 500 Hz CW Filter Tested RL Drake MSRP: Now: $49.99 Was: This RL Drake R-4C FL-500, 500 Hz CW Filter Has been Tested in a Drake R-4C Receiver, and is in good Condition. The Foam that Drake put under the filter brackets has made the writing hard to read. MSRP: Now: $49.99 Was: Add to Cart Quick view Qty in Cart: 0 Quantity: Decrease Quantity: Increase Quantity: Price: MSRP: Now: $49.99 Was: Subtotal: Add to Cart