This heavy weight pre cooler is an attachment for your glass bong. Warning, this pre cooler is heavy in weight and therefore will only fit safely on heavy duty, large bongs. The pre cooler has a male and female 18.8mm ground joint. The male joint is set at an angle for placement onto your bong. This piece stands 160mm tall, is 5mm in glass thickness and 50mm in diameter. The pre cooler fitted with an inline perc for optimal smoke diffusion.