Offering DECT phone functionality, plus both waterproof and dustproof features, is a handset from BT.
The BT Elements 1 km Single is an IP67 Rated Cordless Phone with Answering Machine and Nuisance Call Blocker. This cordless phone looks albeit like a normal cordless phone but has one unique feature above most other phones the 1 km Range. The unit is built solid protected from dust and capable of withstanding water immersion between 15 cm
D81
DECT 60 IP
T111
S790 Trio
KX-TG6611
SL610