Degassing tool For Benjamin Marauder precharged pneumtic air pistol (BP2220) and Crosman Silhouette PCP air pistol (1700P) Will not fit the Marauder air rifle If you need to remove air from your PCP pistol, you'll need this degassing tool. Reasons to use the degasser include transporting your gun via air travel and shipping your gun. Both circumstances require your airgun's reservoir to be empty. Also, if you've overfilled your gun's air reservoir, the degasser will safely and quickly remove the excess air.