Vandy Vape Capstone RDA,designed by VAPE HAPPY, diameter 24mm.
Features:
1.Waterfall Squonk Action
2.Single Screw Spring Loaded Capstone Deck
3.Ramp Airflow System
4.1 Piece PC Comp Cap
5.Dual Slotted Trapezoid Airflow (Single/Dual Coil Compatible)
You can check it here