DECT model is KXTG155SK, which is the same as KXTG7645
The Panasonic DECT cordless is DECT model KXTG155SK, which is the same as KXTG7645. There are several versions, collected under the 76 series. The differences seem to be how many handsets are included with the product. The KXTG155SK (or KXTG7645) has a base and four remotes.