Neptune Triple Sleeper Bunk Bed. Available Colours: Oak Effect & White. Safety Rails On Top Bunk. Top Bunk – Single Bed. Bottom Bunk – Small Double Bed. It can be split into 2 beds if required. Height Below Siderail: 28.5cm. Height Of Bed Base: 33.5cm. Height Below Bed Base: 27cm. Head/Footboard Height: 75.5cm. Height Between Bed Bases: 75cm. Slat Size: 7cm x 1.8cm. Bottom Bed 4′ / Top Bed 3. 1 x Neptune Triple Sleeper Bunk Bed.