25W Heat Pad with Temperature Controller – 30cm Waterproof Mat for Fermentation, Fits Glass & Plastic Fermenters, Carboys, Buckets – Adjustable Temp 0-42°C, Includes NTC Probe & HolderThis easy to use heat pad with a temperature controller is designed to keep your brew warm at a pre set desired temperature for consistent fermentation at a low cost, as the heat pat is only 25 watt. The PVC surface is waterproof (but the pad is not suitable to use in liquid). An internal temperature safety will shut off the power if the heat pad's surface temperature is above 70 (+ 5) . The diameter of the heat pad is 30cm (12'') and it is suitable