This is a 45 mL modification of the 23 mL, 4749 PTFE lined bomb for users who want additional capacity in this popular model. It is made with the same closure as the 23 mL bomb, using a similar thick-walled PTFE cup, 3-3/4 inches deep inside, with a broad flanged seal. Safety blow out protection is provided with a rupture disc that will release pressure through an opening in the cover. Its maximum temperature and pressure ratings, 250°C and 1800 psig, are the same as for the 4749 model. The 4744 bomb is sealed by turning the screw cap down until it is hand tight, then tightening the cap not more than one- eighth turn with a hook spanner. The spanner and holding fixture required for this operation are the same as used with the 4749 bomb. These accessories must be ordered separately.