Inserts are used for low-temperature dabs that cook the oil inside the inserts and keeping the banger from getting dirty Small - 13mm size fit perfectly on AFM Flat Top Bell-Bottom Banger Big - 18mm size fit perfectly on AFM Bell-Bottom Pearls - quartz ball spins around the banger White insert - 18mm size - White bottom quartz Reactor - add more heat to your banger Peak Insert - for use with the Puffco Peak