Summary NOTE: I ADDED CAPTURES FOR 8MM NEODIMIUM MAGNETS TO CREATE A MAGNETIC CLOSURE FOR GRENADE. 9/28/16 This is an updated "hollow" version of The Holy Hand Grenade of Antioch from Monty Python and the Holy Grail. I decided to add in a sound chip on which you can record whatever you want that will activate when you pull the cross pin out. Please note you will need to purchase both a sound module $2 on ebay, see link below and you will need to create the metal tabs to replace the basic switch that comes with the sound board. I've indicated how mine contacts are designed in two images. The first image shows the contacts closed with no pin the second shows them separated with the pin in place.There is also an image which shows both the speaker and sound module placement within the grenade (see through gray). Please note I have not built this yet so I cannot guarantee the placement of the board mount is perfect, but my guess is it should be close. Print this and take your holy hand grenade to the next level. 10secs 10s Sound Voice Audio Recordable Recorder Module Chip for Card New http://r.ebay.com/Heh99k