Saltwater resistant 10 cm (4") full-range driver with glas fibre cone, plastic basket and grille. Balanced frequency response, high efficiency and good high-midrange reproduction. Long time weather proved and therefore especially suited for out-door sound  reinforcement systems, swimming pools, sauna and speaker for boats,  ships and open vehicles. Also suitable for model boat applications. 120  °C temperature resistant.  
Typical applications: 
- Outdoor sound reinforcement systems
- Speaker systems for saunas
- Weatherproof network column speakers
- Boats, ships and open vehicles
Attributes: 
- suitable for outdoor applications, seawater proof
- functionally at low temperature according to EN 60068-2-1 (-40 °C; 96 h)
- up to the standards of the Germanischer Lloyd (requirements for electrical equipment / low temperature)
- Plastic: PC (UL 94: V-0)
- ball-resistant
*) IP protection class for front side when built into a sealed enclosure
| Technical Data: | 
|---|
                                                   | Rated power | 25 W | 
                        | Maximum power | 50 W | 
                                 | Nominal impedance Z | 4 Ohm | 
                                  | Frequency response | 90–19000 Hz | 
                                 | Mean sound pressure level | 90 dB (1 W/1 m) | 
                             | Opening angle (-6 dB) | 64°/4000 Hz | 
                             | Excursion limit | +/−3 mm | 
                        | Resonance frequency fs | 169 Hz | 
                        | Magnetic induction | 1,0 T | 
                        | Magnetic flux | 190 µWb | 
                        | Height of front pole-plate | 3 mm | 
                        | Voice coil diameter | 20 mm | 
                        | Height of winding | 5 mm | 
                        | Cutout diameter | 92 mm | 
                        | Net weight | 0,36 kg | 
                        | D.C. resistance Rdc | 3,4 Ohm | 
                        | Mechanical Q factor Qms | 8,29 | 
                        | Electrical Q factor Qes | 1,02 | 
                        | Total Q factor Qts | 0,91 | 
                        | Equivalent volume Vas | 2 l | 
                        | Effective piston area Sd | 57 cm² | 
                        | Dynamically moved mass Mms | 2,4 g | 
                        | Force factor Bxl | 3,8 Tm | 
                        | Inductance of the voice coil L | 0,2 mH | 
                                                                                                                                                                                                       | Protective system | IP 65 *) | 
                         | Temperature range | −40 ... 120 °C | 
                                                           | Colour | schwarz / black |