Called the CTW range, there are six tweeters, measuring from 30.5 x 30.5mm to 58.8 x 58.8 mm, and between 13.5 to 24mm from front to back.
Oval, rectangular and round frame shapes are available, some with ferrite magnets and others with neodymium types, with cones of and paper, polyester or silk.
Resonant frequencies span 1.3 to 1.7kHz, and frequency response can extend to 20kHz.
Nominal input is 10 or 20W, into 4, 6 or 8Ω. With 1W input, sound pressure levels from 81 up to 89dB are possible (measured at 1m).
The photo shows CTW-403614-206SE (84dB SPL, 20W 6Ω, 1.5kHz, polyester cone, rectangle 40 x 36.5 x 14mm) on the left and on the right, CTW-5424-108SE (89dB SPL, 10W, 8Ω, 1.3kHz, paper cone, round 58.8 x 58.8 x 24mm)
This link currently takes you to the CUI tweeters, and the company has put together a helpful selection of audio guides which are worth a browse.