Abstract: A plurality of circumferentially spaced hooks (32, 36) extend upwardly from a ring (14) to which netting (18) is attached. A pair of retaining devices (40) are carried by the ring (14) and are circumferentially spaced from each other and from the hooks (32, 36). One of the hooks (32) may be pivotable to aid in installing and removing the attachment (12). The retaining devices (40) comprise a coil torsion spring (52) from which an integral latch member (54) extends. The member (54) terminates in a cradle (58) that is biased to pivot upwardly into engagement with the lower surface of the hoop (2). In an alternate embodiment, each retaining device (72) includes a flat spring (74) that bends radially inwardly and is biased radially outwardly to urge a hard rubber engagement portion (76) against the hoop (2). The attachment (12, 12') may be provided in combination with an installation pole (60, 82). The pole (60) engages the pivotal hook housing (28) to pivot the hook (32).