Type A - Material: ABS + elastic band, simple operation, sound vibration reminder, built-in button battery Type B - Material: ABS, Product size: 5.5 * 4.5 * 2.5cm, rechargeable, lithium battery 300mah, selling point: watch design, easy to wear, vibration, lighting, child lock function, suitable for infants, the elderly, etc Better Sleep This Bed Wetting Alarm will help your child stay dry and comfortable throughout the night. It has a wireless sensor that clips to the underwear and a wireless receiver that sounds or vibrates when wetness is detected. This wireless bedwetting alarm is ideal for children, elders, and patients who need daily care and want to overcome bedwetting problems. Easy to Operate With the Bed Wetting Alarm, you can nap with confidence. Just clip the urine sensor along the edge of the underwear and wear the watch receiver on your hand. The alarm will alert you when it detects wetness, so you can change quickly and easily. It is a convenient and easy-to-operate solution for children who wet the bed.