Note: This product is a set of 2. Order number of "1", you will receive 2 coils. (Selling unit has changed from December 25, 2017). SOLEN Hollow Core Coil [18AWG] This is an air core coil made by SOLEN, a veteran of Canadian network parts manufacturers. SOLEN is the worlds first manufacturer of electronic passive parts using the winding technology to create a hollow core coil of "honeycomb structure" using the perfect hexagonal winding technology. This advanced concept (PERFECT LAY HEXAGONAL WINDING) was introduced to design and produce the most complete line of premium quality hollow core coils with very small production tolerances for specific applications in the loudspeaker industry. This high performance hollow core coil (+/-1% tolerance) is available in a wide range of 0.1 mH to 15 mH (18 AWG), so you can use it to design and produce your original network. In addition, all coils are terminated (after removing the enamel coating and then solder-plated) so that they are easy to incorporate into the network, so you dont have to deal with termination by yourself like the traditional SOLEN" coil. General Specifications: Type: Empty coil; Coil winding: OFC single wire; Wire diameter: 18 AWG (1.02 mm); Conductor: Red polyurethane, polyamide enamel; Construction: Hollow cylindrical construction, radial lead wire; Winding structure: Perfect layer hexagonal shape (self-supporting type); Coating: Varnish (dipping); Black and nylon ties (4 pieces). ■Lead wire: O FC single wire/wire diameter: 18 AWG (0.02 mm) / Manufacturing tolerance: +/-1.0%