A compression fitting comprising: a fitting body (100, 200, 300, 400, 501) having a first end (101, 201, 301, 401), a second end (103, 203, 303, 403), an outer surface and an inner surface (107, 207, 307, 407), the inner surface (107, 207, 307, 407) defining a passageway (109, 209, 309, 409) through the fitting body (100, 200, 300, 400, 501) between the first end (101, 201, 301, 401) and second end (103, 203, 303, 403); a ferrule (110, 210, 310, 410, 510) having a first end (111, 211, 311, 411), a second end (113, 213, 313, 413), an outer surface, and an inner surface (117, 317, 417), the inner surface defining a passageway (119, 219, 419) through the ferrule (110, 210, 310, 410, 510) between the first end (111, 211, 311, 411) and second end (113, 213, 313, 413); wherein one of the second end of the fitting body (103, 203, 303, 403) and the first end of the ferrule (111, 211, 311, 411) includes an inner circumferential recess (102, 212, 302, 402) and the other of the first end of the ferrule (111, 211, 311, 411) and the second end of the fitting body (103, 203, 303, 403) includes a coupling extension (112, 202, 312, 412) configured to flex inward and removably engage the inner circumferential recess (102, 212, 302, 402); and a tube (120, 220, 320, 420) disposed through the fitting body passageway (109, 209, 309, 409) and the ferrule passageway (119, 219, 419), the tube (120, 220, 320, 420) having an outer surface (125, 225, 325, 425) with a diameter selected to closely fit through the passageway (109, 209, 309, 409) of the fitting body (100, 200, 300, 400, 501) and the passageway (119, 219, 419) of the ferrule to prevent the coupling extension (112, 202, 312, 412) from flexing inwards to thereby prevent separation of the ferrule (110, 210, 310, 410, 510) and the fitting body (100, 200, 300, 400, 501); wherein the coupling extension (112, 202, 312, 412) includes a plurality of coupling members (114, 204, 314, 414) each separated by slots (116, 206) configured to allow each of the plurality of coupling members (114, 204, 314, 414) to flex towards the interior of the passageway (119, 219, 419) of the ferrule (110, 210, 310, 410, 510) or towards the interior of the passageway (109, 209, 309, 409) of the fitting body (100, 220, 320, 420). a fitting body (100, 200, 300, 400, 501) having a first end (101, 201, 301, 401), a second end (103, 203, 303, 403), an outer surface and an inner surface (107, 207, 307, 407), the inner surface (107, 207, 307, 407) defining a passageway (109, 209, 309, 409) through the fitting body (100, 200, 300, 400, 501) between the first end (101, 201, 301, 401) and second end (103, 203, 303, 403); a ferrule (110, 210, 310, 410, 510) having a first end (111, 211, 311, 411), a second end (113, 213, 313, 413), an outer surface, and an inner surface (117, 317, 417), the inner surface defining a passageway (119, 219, 419) through the ferrule (110, 210, 310, 410, 510) between the first end (111, 211, 311, 411) and second end (113, 213, 313, 413); wherein one of the second end of the fitting body (103, 203, 303, 403) and the first end of the ferrule (111, 211, 311, 411) includes an inner circumferential recess (102, 212, 302, 402) and the other of the first end of the ferrule (111, 211, 311, 411) and the second end of the fitting body (103, 203, 303, 403) includes a coupling extension (112, 202, 312, 412) configured to flex inward and removably engage the inner circumferential recess (102, 212, 302, 402); and a tube (120, 220, 320, 420) disposed through the fitting body passageway (109, 209, 309, 409) and the ferrule passageway (119, 219, 419), the tube (120, 220, 320, 420) having an outer surface (125, 225, 325, 425) with a diameter selected to closely fit through the passageway (109, 209, 309, 409) of the fitting body (100, 200, 300, 400, 501) and the passageway (119, 219, 419) of the ferrule to prevent the coupling extension (112, 202, 312, 412) from flexing inwards to thereby prevent separation of the ferrule (110, 210, 310, 410, 510) and the fitting body (100, 200, 300, 400, 501); wherein the coupling extension (112, 202, 312, 412) includes a plurality of coupling members (114, 204, 314, 414) each separated by slots (116, 206) configured to allow each of the plurality of coupling members (114, 204, 314, 414) to flex towards the interior of the passageway (119, 219, 419) of the ferrule (110, 210, 310, 410, 510) or towards the interior of the passageway (109, 209, 309, 409) of the fitting body (100, 220, 320, 420).