PEI (Polyetherimide) , also known as Ultem, is a reusable, relatively maintenance free. Perfect build surface for both ABS ( Heatbed 100°C) and pPLA (Heatbed °60), other materials such as Metal, Wood, ABS+, ASA,PETG and many others also works just fine. PEI sheet is appealing due to its “no-surface-prep” conditions, which make it convenient to work with. Additionally, printing on PEI sheet requires no support rafts as parts adhere directly to the surface with no issue. Say good bye to Blue Tape and ABS Slurry. Last couple months to years depend on the usage.