SPR-10TW Alpine designed their Type-R SPR-10TW tweeters

1″ silk dome tweeters (pair)
flush-, top-, and bottom-mount hardware included
external crossovers with 4-way level control
power handling: 5-150 watts RMS (450 watts peak power)
frequency response: 1,000-29,000 Hz
impedance: 4 ohms
sensitivity: 88 dB
flush-mount depth: 11/16″