Harvia's Cilindro PC70 in BlackSteel — a Finnish-made pillar heater with the elements wrapped inside an open stone cage. The pillar form lets you embed the heater into the bench or stand it in front of the glass wall for a sculptural look, and the open cage radiates heat 360° rather than aiming it at one face like a wall-mounted heater would. Built-in controls; 80 kg of olivine-diabase stones supplied.

Harvia's Cilindro PC90 in BlackSteel — same pillar form as the 6.8 kW PC70, scaled up for larger four- to six-person cabins. The taller stone cage holds 90 kg, giving you the deep thermal mass that defines a proper Baltic löyly: water hits hot stones, releases as a soft burst of steam, and the cabin holds temperature even after the burst. Built-in controls; stones supplied.

Harvia's Linear 18 Compact in black steel, the wood burner Hekla pairs with the cube cabins. A 14.3 kW Finnish-made stove with a double-shell construction that lets it sit much closer to the cabin walls than a single-shell unit, so the cabin's usable space is preserved. 74.3% combustion efficiency and BImSchV 2 emissions compliance mean the löyly stays dry, the firebox runs clean, and the smoke is well within current UK limits. Comes with the flue kit, roof-penetration sleeve and floor heat shield sized for cube-cabin geometry. Supplied uninstalled; combustion appliances in the UK should be fitted by a HETAS-registered installer, and arranging that is the customer's responsibility.