Use these sort of like Doors - They have IDs, so Doors can lead to them, through you can’t travel from them. Use your wrench to set their ID.
Objective Marker price in Growtopia: sells for about 50 WL (median of 160 offers from community Discords, past 30 days). Live price chart and the latest buy and sell offers.
Recently sold at: NVA, TILW, 3OHI, QALDEN, LOQBG